Blending elastomers with phase change materials offers a modular approach to fabricating smart materials, such as shape memory polymers. This study compares shape memory polymers prepared by peroxide cross-linking a blend of polybutadiene and n-tetracosane (compounded samples) versus swelling peroxide cross-linked polybutadiene in n-tetracosane (swollen samples). Characterization of the thermal, thermomechanical, and shape memory behavior of the two types of samples show very similar behavior as a function of polybutadiene content. The sample with ca. 30% polybutadiene displayed shape memory metrics of ~90% fixity and ~99% recovery at 25% applied strain. The main difference in the samples was the change in fixity and recovery with cycling where they were heated and cooled using water baths. The compounded samples exhibited a 1.4% decrease in fixity, 0.2% decrease in recovery, and 2.25% weight loss over 20 cycles. In contrast, the swollen samples have a 4.2% decrease in fixity, 0.4% decrease in recovery, and 5.63% weight loss over 20 cycles. This weight loss was attributed to the expulsion of the n-tetracosane that experienced a higher driving force in the swollen sample with stretched chains. The cyclic and long-term aging of these polymers is different depending on the preparation method to incorporate the n-tetracosane into the material.
{"title":"Comparison of Swollen vs. Compounded Cross-linked High-Cis-1,4-Polybutadiene/n-Tetracosane Shape Memory Polymers","authors":"Sayan Basak, Kevin A. Cavicchi","doi":"10.1002/pol.20240820","DOIUrl":"https://doi.org/10.1002/pol.20240820","url":null,"abstract":"Blending elastomers with phase change materials offers a modular approach to fabricating smart materials, such as shape memory polymers. This study compares shape memory polymers prepared by peroxide cross-linking a blend of polybutadiene and <i>n</i>-tetracosane (compounded samples) versus swelling peroxide cross-linked polybutadiene in <i>n</i>-tetracosane (swollen samples). Characterization of the thermal, thermomechanical, and shape memory behavior of the two types of samples show very similar behavior as a function of polybutadiene content. The sample with ca. 30% polybutadiene displayed shape memory metrics of ~90% fixity and ~99% recovery at 25% applied strain. The main difference in the samples was the change in fixity and recovery with cycling where they were heated and cooled using water baths. The compounded samples exhibited a 1.4% decrease in fixity, 0.2% decrease in recovery, and 2.25% weight loss over 20 cycles. In contrast, the swollen samples have a 4.2% decrease in fixity, 0.4% decrease in recovery, and 5.63% weight loss over 20 cycles. This weight loss was attributed to the expulsion of the <i>n-</i>tetracosane that experienced a higher driving force in the swollen sample with stretched chains. The cyclic and long-term aging of these polymers is different depending on the preparation method to incorporate the <i>n</i>-tetracosane into the material.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"24 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The lack of endothelial layer hinders the use of decellularized corneal stroma in keratoplasty, resulting in adverse effects, such as non-specific protein adsorption and corneal oedema after implantation, which leads to rapid failure of the ophthalmic implants. In this study, superhydrophilic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) was gently introduced to the porcine-derived decellularized corneal stroma matrix (pDCSM), aiming to resist undesirable biofilm adsorption within the ocular environment. After complete decellularization, the pDCSM was first methacrylated by the integration of methacrylic anhydride. Consecutively, PMPC was only grafted from the back surface (endothelium side) of the methacrylated pDCSM through surface-initiated free radical polymerization. This one-side surface-modified pDCSM not only retained good optical transmittance and mechanical properties that were comparable to the untreated pDCSM, but both surfaces of the same artificial cornea also showed non-cytotoxicity and good biocompatibility. Moreover, the PMPC-grafted back surface exhibited considerable antifouling properties that resisted both protein and cell adhesion. Consequently, such Janus-like artificial cornea holds great promise in future ophthalmic applications, which may serve as a springboard for the design of versatile decellularized extracellular matrix based biomedical implants with Janus-like properties.
{"title":"Introducing Antifouling Properties Onto Janus-Like Decellularized Corneas via Graft-From Zwitterionic Polymers","authors":"Simin Wu, Jiandong Han, Xiukai Guo, Zilong Rao, Kexin Zhang, Daping Quan, Ying Bai","doi":"10.1002/pol.20240720","DOIUrl":"https://doi.org/10.1002/pol.20240720","url":null,"abstract":"The lack of endothelial layer hinders the use of decellularized corneal stroma in keratoplasty, resulting in adverse effects, such as non-specific protein adsorption and corneal oedema after implantation, which leads to rapid failure of the ophthalmic implants. In this study, superhydrophilic poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) was gently introduced to the porcine-derived decellularized corneal stroma matrix (pDCSM), aiming to resist undesirable biofilm adsorption within the ocular environment. After complete decellularization, the pDCSM was first methacrylated by the integration of methacrylic anhydride. Consecutively, PMPC was only grafted from the back surface (endothelium side) of the methacrylated pDCSM through surface-initiated free radical polymerization. This one-side surface-modified pDCSM not only retained good optical transmittance and mechanical properties that were comparable to the untreated pDCSM, but both surfaces of the same artificial cornea also showed non-cytotoxicity and good biocompatibility. Moreover, the PMPC-grafted back surface exhibited considerable antifouling properties that resisted both protein and cell adhesion. Consequently, such Janus-like artificial cornea holds great promise in future ophthalmic applications, which may serve as a springboard for the design of versatile decellularized extracellular matrix based biomedical implants with Janus-like properties.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"32 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiale Li, Qiang Ma, Guohe Xu, Chunqiang Jiang, Mengru Wang
High-voltage responsiveness and poor mechanical properties hindered the practical applications of electro-induced shape-changing hydrogels (EISCHs). In previous work, mechanical properties were improved simply by increasing the degree of crosslinking, which resulted in reduced deformation capacity. Therefore, the nanocomposite technique of reinforcing nondeformable hydrogels' mechanical properties was introduced into EISCHs, resulting in the successful synthesis of Poly (N-isopropylacrylamide-co-5-acrylamido-1,10-phenanthroline bis (1,10-phenanthroline) iron (II))/hydrophilic-treated hydroxylated carbon nanofibers (P(NIPAM-Fe(phen)3)/HMWCNFs) nanocomposite shape-changing hydrogel that exhibits outstanding mechanical properties, doesn't have its deformation ability weakened and possesses low-voltage responsiveness in this work. The impact of various hydrophilic-treated hydroxylated carbon nanofibers (HMWCNFs) content on hydrogels' structure, swelling, crosslinking, mechanics and electro-induced shape-changing properties was investigated. As the HMWCNFs content increased (0.2%–1.0%), the tensile and compressive strengths increased, marking 6.67 times and 2.91 times rise over hydrogel without HMWCNFs. The deformation ability of P(NIPAM-Fe(phen)3/HMWCNFs) hydrogel was higher than without HMWCNFs at minimum response voltage 10 V. The physical entanglements and hydrogen bonding between HMWCNFs and polymer chains reduced adhesion energy and provided energy dissipation. HMWCNFs, as a conductive filler, facilitated electron transfer. The hydrogel swelled and shrank due to the transition between 5-acrylamido-1,10-phenanthroline bis (1,10-phenanthroline) iron (II) (Fe(phen)3) network iron (II) and iron (III) states under low-voltage stimulation.
{"title":"Preparation and Characterization of Low-Voltage Responsive Nanocomposite Shape-Changing Hydrogels/Carbon Nanofibers With Enhanced Mechanical Properties","authors":"Jiale Li, Qiang Ma, Guohe Xu, Chunqiang Jiang, Mengru Wang","doi":"10.1002/pol.20240746","DOIUrl":"https://doi.org/10.1002/pol.20240746","url":null,"abstract":"High-voltage responsiveness and poor mechanical properties hindered the practical applications of electro-induced shape-changing hydrogels (EISCHs). In previous work, mechanical properties were improved simply by increasing the degree of crosslinking, which resulted in reduced deformation capacity. Therefore, the nanocomposite technique of reinforcing nondeformable hydrogels' mechanical properties was introduced into EISCHs, resulting in the successful synthesis of Poly (N-isopropylacrylamide-co-5-acrylamido-1,10-phenanthroline bis (1,10-phenanthroline) iron (II))/hydrophilic-treated hydroxylated carbon nanofibers (P(NIPAM-Fe(phen)<sub>3</sub>)/HMWCNFs) nanocomposite shape-changing hydrogel that exhibits outstanding mechanical properties, doesn't have its deformation ability weakened and possesses low-voltage responsiveness in this work. The impact of various hydrophilic-treated hydroxylated carbon nanofibers (HMWCNFs) content on hydrogels' structure, swelling, crosslinking, mechanics and electro-induced shape-changing properties was investigated. As the HMWCNFs content increased (0.2%–1.0%), the tensile and compressive strengths increased, marking 6.67 times and 2.91 times rise over hydrogel without HMWCNFs. The deformation ability of P(NIPAM-Fe(phen)<sub>3</sub>/HMWCNFs) hydrogel was higher than without HMWCNFs at minimum response voltage 10 V. The physical entanglements and hydrogen bonding between HMWCNFs and polymer chains reduced adhesion energy and provided energy dissipation. HMWCNFs, as a conductive filler, facilitated electron transfer. The hydrogel swelled and shrank due to the transition between 5-acrylamido-1,10-phenanthroline bis (1,10-phenanthroline) iron (II) (Fe(phen)<sub>3</sub>) network iron (II) and iron (III) states under low-voltage stimulation.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"7 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yifei Jin, Gaohui Sun, Guocheng Zhou, Rongrong Chen, Jun Wang, Zailin Yang, Shihui Han
In this study, the hydroxyl modified hollow glass microsphere (HM-HGM) is added to different foaming slurries of isocyanate-based polyimide foam (IBPIF) at varying ratios, and different bonding effects are formed to optimize the dispersion behavior. Then, the novel HGM composited IBPIF (IBPIF/HGM) is prepared. Hydroxyl groups on HM-HGM establish hydrogen bonding effect with pyromellitic acid dimethyl ester and dimethyl formamide in the white slurry and react with isocyanate groups in the black slurry. The cell structure of IBPIF is altered to improve its sound absorption performance and mechanical behaviors. Compared with IBPIF/HGM-0, the average cell size of IBPIF/HGM-1 and BPIF/HGM-5 decreases significantly. The sound absorption performance and mechanical behaviors of them are improved to some extent. Compared with samples in which the HM-HGM is added alone to a single slurry, when the dosage ratio of HM-HGM in black and white slurries is 1:1, IBPIF/HGM-3 has more uniform cell structure. The change of IBPIF cell structure by the introduction of HM-HGM and the unique structure of HM-HGM can enhance the sound absorption performance and mechanical behaviors of IBPIF. The design idea of different bonding mechanisms significantly provides technical assistance to enhance the acoustic performance of polymeric foam materials.
{"title":"Fabrication of Hydroxyl Modified Hollow Glass Microsphere Composite Isocyanate-Based Polyimide Foam and Optimization Strategy Based on Different Bonding Mechanisms","authors":"Yifei Jin, Gaohui Sun, Guocheng Zhou, Rongrong Chen, Jun Wang, Zailin Yang, Shihui Han","doi":"10.1002/pol.20240796","DOIUrl":"https://doi.org/10.1002/pol.20240796","url":null,"abstract":"In this study, the hydroxyl modified hollow glass microsphere (HM-HGM) is added to different foaming slurries of isocyanate-based polyimide foam (IBPIF) at varying ratios, and different bonding effects are formed to optimize the dispersion behavior. Then, the novel HGM composited IBPIF (IBPIF/HGM) is prepared. Hydroxyl groups on HM-HGM establish hydrogen bonding effect with pyromellitic acid dimethyl ester and dimethyl formamide in the white slurry and react with isocyanate groups in the black slurry. The cell structure of IBPIF is altered to improve its sound absorption performance and mechanical behaviors. Compared with IBPIF/HGM-0, the average cell size of IBPIF/HGM-1 and BPIF/HGM-5 decreases significantly. The sound absorption performance and mechanical behaviors of them are improved to some extent. Compared with samples in which the HM-HGM is added alone to a single slurry, when the dosage ratio of HM-HGM in black and white slurries is 1:1, IBPIF/HGM-3 has more uniform cell structure. The change of IBPIF cell structure by the introduction of HM-HGM and the unique structure of HM-HGM can enhance the sound absorption performance and mechanical behaviors of IBPIF. The design idea of different bonding mechanisms significantly provides technical assistance to enhance the acoustic performance of polymeric foam materials.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"38 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Raisa Dvorikova, Galy Markova, Anton Shulgin, Ludmila Komarova, Oleg Baranov, Igor Shchetinin, Dmitry Bagrov, Mikhail Buzin, Zinaida Klemenkova, Yaroslav Mezhuev
A ferrocene-containing oligoorganosiloxane with a number-average degree of polymerization of 8.8 and a number-average molecular weight of 3200 is synthesized by hydrolytic condensation of 3-aminopropyltriethoxysilane followed by chemical modification of the resulting oligomer with acetylferrocene. Its structure is characterized by MALDI-TOF, NMR and IR spectroscopy. 1H NMR spectroscopy shows the predominance of more thermodynamically stable units containing anti-configuration Schiff bases. Using IR spectroscopy as well as experimental determination of surface energy and its polar (acid–base) and dispersion components, the covalent immobilization of ferrocene-containing oligoorganosiloxane on a glass surface after heating at 110°C is shown. The formed coating provides hydrophobization, acid–base indifference of the glass surface and serves as a precursor for the formation of magnetically soft materials after pyrolysis in argon already at 350°C. The main stages of ferrocene-containing oligoorganosiloxane thermal destruction in an inert atmosphere and the formation of a mixture of iron and silicon oxides during its thermal oxidative destruction are established by combination of TGA/DTA, IR spectroscopy and elemental analysis. The proposed approach opens up new possibilities for functionalizing silicates surfaces, creating magnetic glasses, as well as regulating surface energy and its components.
{"title":"Synthesis of Ferrocene-Containing Schiff Bases Based on 3-Aminopropyltriethoxysilane Oligomers for Covalent Modification of Glass Surfaces and Creation of Soft Magnetic Materials","authors":"Raisa Dvorikova, Galy Markova, Anton Shulgin, Ludmila Komarova, Oleg Baranov, Igor Shchetinin, Dmitry Bagrov, Mikhail Buzin, Zinaida Klemenkova, Yaroslav Mezhuev","doi":"10.1002/pol.20240629","DOIUrl":"https://doi.org/10.1002/pol.20240629","url":null,"abstract":"A ferrocene-containing oligoorganosiloxane with a number-average degree of polymerization of 8.8 and a number-average molecular weight of 3200 is synthesized by hydrolytic condensation of 3-aminopropyltriethoxysilane followed by chemical modification of the resulting oligomer with acetylferrocene. Its structure is characterized by MALDI-TOF, NMR and IR spectroscopy. <sup>1</sup>H NMR spectroscopy shows the predominance of more thermodynamically stable units containing <i>anti</i>-configuration Schiff bases. Using IR spectroscopy as well as experimental determination of surface energy and its polar (acid–base) and dispersion components, the covalent immobilization of ferrocene-containing oligoorganosiloxane on a glass surface after heating at 110°C is shown. The formed coating provides hydrophobization, acid–base indifference of the glass surface and serves as a precursor for the formation of magnetically soft materials after pyrolysis in argon already at 350°C. The main stages of ferrocene-containing oligoorganosiloxane thermal destruction in an inert atmosphere and the formation of a mixture of iron and silicon oxides during its thermal oxidative destruction are established by combination of TGA/DTA, IR spectroscopy and elemental analysis. The proposed approach opens up new possibilities for functionalizing silicates surfaces, creating magnetic glasses, as well as regulating surface energy and its components.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"75 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yijia Guan, Hui Guo, Xiaofeng Jia, Jieyi Qin, Yue Yang, Kun Cao, Tao Li, Jianguo Liao, Yanru Zhang
Shape memory polymers (SMPs) are novel kinds of smart materials whose shape can be changed in external conditions such as heat stimulus. Due to their excellent structural versatility and high elastic strain, they have important applications in the field of biomaterials. Here, a series of amorphous shape memory polymer materials are prepared and their shape memory properties and glass transition temperature (Tg) are also investigated. A special kind of epoxy polymer, whose shape can be changed at around physiological temperature, is synthesized by regulating the crosslinking density and introducing flexible aliphatic epoxy chains. The shape memory function of this epoxy polymer is studied by deformation test. In addition, to explore their application in the field of biomedical materials, the biocompatibility of the materials are evaluated, including the effects on the erythrocyte hemolysis rate and cell activity. The experimental results show that this kind of epoxy polymer has good shape memory function and biocompatibility.
{"title":"Regulation of Glass Transition Temperature in Thermo-Responsive Epoxy Shape Memory Polymers: The Roles of Chemical Crosslinking Density and Chain Flexibility","authors":"Yijia Guan, Hui Guo, Xiaofeng Jia, Jieyi Qin, Yue Yang, Kun Cao, Tao Li, Jianguo Liao, Yanru Zhang","doi":"10.1002/pol.20240728","DOIUrl":"https://doi.org/10.1002/pol.20240728","url":null,"abstract":"Shape memory polymers (SMPs) are novel kinds of smart materials whose shape can be changed in external conditions such as heat stimulus. Due to their excellent structural versatility and high elastic strain, they have important applications in the field of biomaterials. Here, a series of amorphous shape memory polymer materials are prepared and their shape memory properties and glass transition temperature (<i>T</i><sub>g</sub>) are also investigated. A special kind of epoxy polymer, whose shape can be changed at around physiological temperature, is synthesized by regulating the crosslinking density and introducing flexible aliphatic epoxy chains. The shape memory function of this epoxy polymer is studied by deformation test. In addition, to explore their application in the field of biomedical materials, the biocompatibility of the materials are evaluated, including the effects on the erythrocyte hemolysis rate and cell activity. The experimental results show that this kind of epoxy polymer has good shape memory function and biocompatibility.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"108 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. P. Fernandez Bordín, E. Rufeil Fiori, J. M. Padró, V.M. Galván Josa, T. S. Plivelic, M. R. Romero
Stimuli-responsive polymers stand out for their ability to respond to small environmental changes. One of the most representative thermo-sensitive materials is poly(N-isopropyl acrylamide) (PNIPAm), which presents reversible phase transitions close to the human body temperature. However, previous studies observed that the copolymerization of NIPAm with small quantities of different monomers like acrylic acid (AAc) results in copolymers with reduced or lost thermo-responsivity. In this study, thermo-sensitive PNIPAm, pH-sensitive poly(acrylic acid) (PAAc), and various proportions of their copolymers P(NIPAm-co-AAc) were obtained by free radical polymerization and thoroughly characterized. Rheological and structural studies reveal the remaining thermosensitivity of the copolymers manifested at short molecular ranges. These alterations in short-range interactions are observed in all samples containing NIPAm, and they are evidenced by changes in the fractality of their structure and flow index behavior of the Viscosity Ostwald–de Waele Model. Particularly, when the copolymer proportion of NIPAm/AAc is about 40/60, the Beaucage model reveals two structural levels, ~200 and ~10 nm. Furthermore, the model exhibits a thermal response of the lower-size substructures, indicating possible segregation of NIPAm-rich regions from copolymer chains. The evidence found in this work could contribute to the development of nanosystems, in which local thermoresponsive effects are sought, such as for active drug targeting.
{"title":"Localized Thermoresponsive Behavior in P(NIPAm-co-AAc) Copolymers: Structural Insights From Rheology and Small Angle X-Ray Scattering","authors":"S. P. Fernandez Bordín, E. Rufeil Fiori, J. M. Padró, V.M. Galván Josa, T. S. Plivelic, M. R. Romero","doi":"10.1002/pol.20240799","DOIUrl":"https://doi.org/10.1002/pol.20240799","url":null,"abstract":"Stimuli-responsive polymers stand out for their ability to respond to small environmental changes. One of the most representative thermo-sensitive materials is poly(<i>N</i>-isopropyl acrylamide) (PNIPAm), which presents reversible phase transitions close to the human body temperature. However, previous studies observed that the copolymerization of NIPAm with small quantities of different monomers like acrylic acid (AAc) results in copolymers with reduced or lost thermo-responsivity. In this study, thermo-sensitive PNIPAm, pH-sensitive poly(acrylic acid) (PAAc), and various proportions of their copolymers P(NIPAm-<i>co</i>-AAc) were obtained by free radical polymerization and thoroughly characterized. Rheological and structural studies reveal the remaining thermosensitivity of the copolymers manifested at short molecular ranges. These alterations in short-range interactions are observed in all samples containing NIPAm, and they are evidenced by changes in the fractality of their structure and flow index behavior of the Viscosity Ostwald–de Waele Model. Particularly, when the copolymer proportion of NIPAm/AAc is about 40/60, the Beaucage model reveals two structural levels, ~200 and ~10 nm. Furthermore, the model exhibits a thermal response of the lower-size substructures, indicating possible segregation of NIPAm-rich regions from copolymer chains. The evidence found in this work could contribute to the development of nanosystems, in which local thermoresponsive effects are sought, such as for active drug targeting.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"20 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The growing demand for lipid–polymer conjugates (LPCs) in biomedicine highlights the need for efficient synthesis methods. This study presents a novel Y-type photoiniferter reagent (Lipid-PIT) with a diethyldithiocarbamate group and a diacylglycerol group. Lipid-PIT efficiently initiated the polymerization of vinyl monomers such as oligo(ethylene glycol) methacrylate (OEGMA), N,N-dimethylacrylamide (DMA), tert-butyl acrylate (tBA), and n-butyl acrylate (nBA) under UV irradiation at room temperature, yielding LPCs. Proton NMR confirmed the presence of diethyldithiocarbamate and diacylglycerol moieties at the chain ends. The polymerization kinetics of DMA showed a linear increase in molecular weight (Mn) with time, with a polydispersity (Đ) below 1.50, demonstrating high controllability. Moreover, Lipid-PIT allows for the creation of block copolymers via secondary chain extension. In vitro assays revealed that LPCs synthesized from OEGMA monomers successfully modified L929 and HeLa cell surfaces and exhibited good biocompatibility. This study offers a rapid, efficient method for LPC synthesis with promising biomedical applications.
{"title":"Preparation of Lipid–Polymer Conjugates by Photoiniferter Polymerization and Application to Cell Surface Modification","authors":"Wenjin Wang, Shengjie Liu, Yijia Yu, Wenjuan Xia, Zhaoqiang Wu, Hong Chen","doi":"10.1002/pol.20240850","DOIUrl":"https://doi.org/10.1002/pol.20240850","url":null,"abstract":"The growing demand for lipid–polymer conjugates (LPCs) in biomedicine highlights the need for efficient synthesis methods. This study presents a novel Y-type photoiniferter reagent (Lipid-PIT) with a diethyldithiocarbamate group and a diacylglycerol group. Lipid-PIT efficiently initiated the polymerization of vinyl monomers such as oligo(ethylene glycol) methacrylate (OEGMA), <i>N</i>,<i>N</i>-dimethylacrylamide (DMA), <i>tert</i>-butyl acrylate (tBA), and <i>n</i>-butyl acrylate (<i>n</i>BA) under UV irradiation at room temperature, yielding LPCs. Proton NMR confirmed the presence of diethyldithiocarbamate and diacylglycerol moieties at the chain ends. The polymerization kinetics of DMA showed a linear increase in molecular weight (<i>M</i><sub>n</sub>) with time, with a polydispersity (Đ) below 1.50, demonstrating high controllability. Moreover, Lipid-PIT allows for the creation of block copolymers via secondary chain extension. In vitro assays revealed that LPCs synthesized from OEGMA monomers successfully modified L929 and HeLa cell surfaces and exhibited good biocompatibility. This study offers a rapid, efficient method for LPC synthesis with promising biomedical applications.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"17 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mechanical properties are crucial for the application of nanocellulose aerogels. In this work, a series of nanocellulose aerogels with solid content concentration gradient (0.5, 1.0, 1.5, 2.0 wt%) of precursor dispersion are prepared by freeze-drying method, and the effect of nanocellulose solid content on the mechanical properties of nanocellulose aerogels was investigated. As the solid content concentration increased, the internal microstructure of the aerogel underwent a transition from a sparse reticular structure to a tightly arranged lamellar structure. This transition led to a substantial improvement in the mechanical properties of the aerogel. At 50% strain, the compressive strength of the aerogel increased from 8.4 to 37.56 kPa with the increase of nanofibrillar cellulose solid content. Furthermore, the specific strength, specific modulus, and compressive modulus also increased, while maintaining a low density (20.02 mg/cm3) and high porosity (98.63%). This work confirms the feasibility of structural strengthening and mechanical property enhancement of nanocellulose aerogels by density modification, which provides a guidance for the design of durability enhancement of nanocellulose aerogels for broadening their application fields.
{"title":"Density Modifications Toward High Mechanical Performance Nanocellulose Aerogels","authors":"Gaigai Duan, Qin Qin, Rubei Hu, Zhao Liang, Xiaoshuai Han, Haoqi Yang, Yong Huang, Chunmei Zhang, Shuijian He, Shaohua Jiang","doi":"10.1002/pol.20240736","DOIUrl":"https://doi.org/10.1002/pol.20240736","url":null,"abstract":"Mechanical properties are crucial for the application of nanocellulose aerogels. In this work, a series of nanocellulose aerogels with solid content concentration gradient (0.5, 1.0, 1.5, 2.0 wt%) of precursor dispersion are prepared by freeze-drying method, and the effect of nanocellulose solid content on the mechanical properties of nanocellulose aerogels was investigated. As the solid content concentration increased, the internal microstructure of the aerogel underwent a transition from a sparse reticular structure to a tightly arranged lamellar structure. This transition led to a substantial improvement in the mechanical properties of the aerogel. At 50% strain, the compressive strength of the aerogel increased from 8.4 to 37.56 kPa with the increase of nanofibrillar cellulose solid content. Furthermore, the specific strength, specific modulus, and compressive modulus also increased, while maintaining a low density (20.02 mg/cm<sup>3</sup>) and high porosity (98.63%). This work confirms the feasibility of structural strengthening and mechanical property enhancement of nanocellulose aerogels by density modification, which provides a guidance for the design of durability enhancement of nanocellulose aerogels for broadening their application fields.","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"11 1","pages":""},"PeriodicalIF":254.7,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<p>Although rates of contralateral prophylactic mastectomy and bilateral mastectomy are increasing among women with unilateral sporadic breast cancer, a new study reports that despite the procedure diminishing the risk of contralateral breast cancer, the patients experienced mortality rates similar to those of patients treated with lumpectomy or unilateral mastectomy.</p><p>The primary goal of the study, appearing in <i>JAMA Oncology</i> (doi:10.1001/jamaoncol.2024.2212), was to determine the 20-year cumulative risk of breast cancer mortality among women with stage 0–III unilateral breast cancer divided by each patient’s initial surgical procedures.</p><p>In an editorial accompanying the study, Seema A. Khan, MD, Bluhm Family Professor of Cancer Research at the Feinberg School of Medicine at Northwestern University in Chicago, Illinois, and Masha Kocherginsky, PhD, professor of biostatistics and director of the Quantitative Data Sciences Core at the Robert H. Lurie Comprehensive Cancer Center at Northwestern Medicine, wrote that although contralateral breast cancer is the most frequent second malignant tumor among women who have experienced a diagnosis of primary breast cancer, it is less frequent and less ominous than recurrence of the initial cancer. “Nevertheless,” they wrote, “for many patients with newly diagnosed unilateral breast cancer, it can be a prominent source of worry as they navigate their treatment decisions. This worry is accentuated among young patients and those with early-stage disease.”</p><p>The cohort study included patients from the Surveillance, Epidemiology, and End Results Program registry database. The researchers identified 661,270 eligible women with unilateral breast cancer diagnosed from 2000 to 2019. The average age of the patients was 58.7 years. In each treatment group, approximately 83% were White, just over 8% were Black, approximately 2% were East Asian, and 2% were Southeast Asian. The remainder of the patients were American Indian/Alaska Native, Pacific Islander, South Asian, or “unknown” (approximately 1% in each category).</p><p>The research team identified 564,062 cases of invasive breast cancer (85.3%) and 97,208 cases of ductal carcinoma in situ (14.7%). According to study author Steven A. Narod, MD, a professor in the Dalla Lana School of Public Health and the Department of Medicine at the University of Toronto, the researchers matched 90.7% of the patients with bilateral mastectomy into three surgical groups of equal size (36,028 women in each treatment group): lumpectomy, unilateral mastectomy, and bilateral mastectomy. All three groups were similar across demographic, clinical, and treatment variables and propensity scores. More than 70% of the cohort had undergone breast-conserving surgery, whereas 23.4% had undergone unilateral mastectomy, and 6.0% had undergone bilateral mastectomy.</p><p>Nearly two-thirds of the patients underwent radiotherapy, whereas approximately 37% received chemotherapy. T
{"title":"Bilateral mastectomy may not reduce mortality risk","authors":"Mike Fillon","doi":"10.3322/caac.21869","DOIUrl":"10.3322/caac.21869","url":null,"abstract":"<p>Although rates of contralateral prophylactic mastectomy and bilateral mastectomy are increasing among women with unilateral sporadic breast cancer, a new study reports that despite the procedure diminishing the risk of contralateral breast cancer, the patients experienced mortality rates similar to those of patients treated with lumpectomy or unilateral mastectomy.</p><p>The primary goal of the study, appearing in <i>JAMA Oncology</i> (doi:10.1001/jamaoncol.2024.2212), was to determine the 20-year cumulative risk of breast cancer mortality among women with stage 0–III unilateral breast cancer divided by each patient’s initial surgical procedures.</p><p>In an editorial accompanying the study, Seema A. Khan, MD, Bluhm Family Professor of Cancer Research at the Feinberg School of Medicine at Northwestern University in Chicago, Illinois, and Masha Kocherginsky, PhD, professor of biostatistics and director of the Quantitative Data Sciences Core at the Robert H. Lurie Comprehensive Cancer Center at Northwestern Medicine, wrote that although contralateral breast cancer is the most frequent second malignant tumor among women who have experienced a diagnosis of primary breast cancer, it is less frequent and less ominous than recurrence of the initial cancer. “Nevertheless,” they wrote, “for many patients with newly diagnosed unilateral breast cancer, it can be a prominent source of worry as they navigate their treatment decisions. This worry is accentuated among young patients and those with early-stage disease.”</p><p>The cohort study included patients from the Surveillance, Epidemiology, and End Results Program registry database. The researchers identified 661,270 eligible women with unilateral breast cancer diagnosed from 2000 to 2019. The average age of the patients was 58.7 years. In each treatment group, approximately 83% were White, just over 8% were Black, approximately 2% were East Asian, and 2% were Southeast Asian. The remainder of the patients were American Indian/Alaska Native, Pacific Islander, South Asian, or “unknown” (approximately 1% in each category).</p><p>The research team identified 564,062 cases of invasive breast cancer (85.3%) and 97,208 cases of ductal carcinoma in situ (14.7%). According to study author Steven A. Narod, MD, a professor in the Dalla Lana School of Public Health and the Department of Medicine at the University of Toronto, the researchers matched 90.7% of the patients with bilateral mastectomy into three surgical groups of equal size (36,028 women in each treatment group): lumpectomy, unilateral mastectomy, and bilateral mastectomy. All three groups were similar across demographic, clinical, and treatment variables and propensity scores. More than 70% of the cohort had undergone breast-conserving surgery, whereas 23.4% had undergone unilateral mastectomy, and 6.0% had undergone bilateral mastectomy.</p><p>Nearly two-thirds of the patients underwent radiotherapy, whereas approximately 37% received chemotherapy. T","PeriodicalId":137,"journal":{"name":"CA: A Cancer Journal for Clinicians","volume":"74 6","pages":"469-470"},"PeriodicalIF":503.1,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.3322/caac.21869","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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