Katia Bacha, Catherine Chemotti, Jean-Pierre Mbakidi, M. Deleu, S. Bouquillon
Dendrimers are increasingly being studied in the context of encapsulation. Many potential applications of dendrimers are based on their properties. They are used in drug delivery systems, cosmetics, food and chemistry. This review is first devoted to different synthesis approaches for dendrimers and to their ability to encapsulate active molecules. Their applications in different fields, as well as their cytotoxicity, are then detailed. To conclude this review, the main works on the interaction of dendrimers with the stratum corneum (SC) are also presented.
{"title":"Dendrimers: Synthesis, Encapsulation Applications and Specific Interaction with the Stratum Corneum—A Review","authors":"Katia Bacha, Catherine Chemotti, Jean-Pierre Mbakidi, M. Deleu, S. Bouquillon","doi":"10.3390/macromol3020022","DOIUrl":"https://doi.org/10.3390/macromol3020022","url":null,"abstract":"Dendrimers are increasingly being studied in the context of encapsulation. Many potential applications of dendrimers are based on their properties. They are used in drug delivery systems, cosmetics, food and chemistry. This review is first devoted to different synthesis approaches for dendrimers and to their ability to encapsulate active molecules. Their applications in different fields, as well as their cytotoxicity, are then detailed. To conclude this review, the main works on the interaction of dendrimers with the stratum corneum (SC) are also presented.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"131 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79617951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rafael Carvalho Alves, C. Contessa, C. C. Moraes, Gabriela Silveira da Rosa
The biggest challenge for scientists is to create an ideal wound dressing that should be non-toxic, biocompatible, and biodegradable, providing optimal conditions for the most effective regeneration process. Biomaterials loaded with plant-derived compounds show better biocompatibility and biological properties, ensuring a faster tissue repair process. In order to develop membranes with good mechanical properties and anti-bacterial properties, the objective of this work describes the synthesis of a chitosan-based membrane added with olive leaf extract as an active principle with potential for topical application. The material developed was characterized in terms of morphology, physical, chemical, and mechanical properties, and the anti-bacterial capacity of the membranes. The results indicated that the developed membrane has good potential for use as a wound dressing, as it presented mechanical properties (30.17 ± 8.73 MPa) and fluid draining capacity (29.31 ± 1.65 g·m−2·h−1) adequacy. In addition, the antimicrobial activity analysis revealed the active membrane potential against E. coli and S. aureus reaching 9.9 mm and 9.1 mm, respectively, in inhibition zones, the most common bacteria in skin wounds. Therefore, all the results indicate that the developed membrane presents viable characteristics for the use of wound dressing.
{"title":"Biopolymeric Membranes with Active Principle of Olive Leaves (Olea europaea L.) for Potential Topical Application","authors":"Rafael Carvalho Alves, C. Contessa, C. C. Moraes, Gabriela Silveira da Rosa","doi":"10.3390/macromol3020020","DOIUrl":"https://doi.org/10.3390/macromol3020020","url":null,"abstract":"The biggest challenge for scientists is to create an ideal wound dressing that should be non-toxic, biocompatible, and biodegradable, providing optimal conditions for the most effective regeneration process. Biomaterials loaded with plant-derived compounds show better biocompatibility and biological properties, ensuring a faster tissue repair process. In order to develop membranes with good mechanical properties and anti-bacterial properties, the objective of this work describes the synthesis of a chitosan-based membrane added with olive leaf extract as an active principle with potential for topical application. The material developed was characterized in terms of morphology, physical, chemical, and mechanical properties, and the anti-bacterial capacity of the membranes. The results indicated that the developed membrane has good potential for use as a wound dressing, as it presented mechanical properties (30.17 ± 8.73 MPa) and fluid draining capacity (29.31 ± 1.65 g·m−2·h−1) adequacy. In addition, the antimicrobial activity analysis revealed the active membrane potential against E. coli and S. aureus reaching 9.9 mm and 9.1 mm, respectively, in inhibition zones, the most common bacteria in skin wounds. Therefore, all the results indicate that the developed membrane presents viable characteristics for the use of wound dressing.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85666628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Using natural materials as reinforcements for polypropylene to alter composite properties and cost is a well-known approach. Often, wood particles are used for that. These give reasonable reinforcement, but are also sought after by other industries, e.g., for energy production, and may also not be available everywhere. Therefore, the aim of this work was to investigate cherry pit particles as an alternative material for polypropylene reinforcement. Cherry pits originate as a by-product from fruit processing and have not been utilized until now as reinforcement. Cherry pit particles were produced by milling the pits, and afterwards composites were produced by compounding and injection molding. Mechanical properties and melt flow were investigated. We found some reinforcement effect, but to a lesser extent than wood particles. The cherry pit particles contain some fatty acid components, which reduce tensile properties and increase the melt flow rate of the composites. For future applications, methods for reducing these fatty acids to improve reinforcement capabilities should be investigated.
{"title":"Feasibility of Cherry Pit Particles as a Natural Reinforcement in Polypropylene","authors":"C. Burgstaller, Károly Renner","doi":"10.3390/macromol3020019","DOIUrl":"https://doi.org/10.3390/macromol3020019","url":null,"abstract":"Using natural materials as reinforcements for polypropylene to alter composite properties and cost is a well-known approach. Often, wood particles are used for that. These give reasonable reinforcement, but are also sought after by other industries, e.g., for energy production, and may also not be available everywhere. Therefore, the aim of this work was to investigate cherry pit particles as an alternative material for polypropylene reinforcement. Cherry pits originate as a by-product from fruit processing and have not been utilized until now as reinforcement. Cherry pit particles were produced by milling the pits, and afterwards composites were produced by compounding and injection molding. Mechanical properties and melt flow were investigated. We found some reinforcement effect, but to a lesser extent than wood particles. The cherry pit particles contain some fatty acid components, which reduce tensile properties and increase the melt flow rate of the composites. For future applications, methods for reducing these fatty acids to improve reinforcement capabilities should be investigated.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"204 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74148890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jéssica de Santana Brito, Amanda de Oliveira Marinho, L. L. de Siqueira Patriota, W. D. C. Gaião, Diego José Lira Torres, P. Paiva, V. D. de Lorena, C. G. Rodrigues, M. B. da Silva, T. Napoleão
Lectins (carbohydrate-binding proteins) are able to distinguish different patterns of glycosylation on cell surfaces. This study investigated the effects of lectins from Alpinia purpurata inflorescence (ApuL) and Schinus terebinthifolia leaf (SteLL) on the viability of human leukemia cells (K562, chronic myeloid leukemia; JURKAT, acute lymphoblastic leukemia) and mesenchymal stem cells (MSCs) from human umbilical cords. In addition, possible immunomodulatory effects of ApuL and SteLL on MSCs were assessed by determining cytokine levels in cultures. ApuL reduced the viability of JURKAT cells (IC50: 12.5 μg/mL), inducing both apoptosis and necrosis. For K562 cells, ApuL at 50 µg/mL caused a decrease in viability, but of only 8.8%. Conversely, SteLL exerted a cytotoxic effect on K562 (IC50: 6.0 μg/mL), inducing apoptosis, while it was not cytotoxic to JURKAT. ApuL and SteLL (0.19–100 μg/mL) did not decrease MSCs viability. Treatment with ApuL strongly suppressed (99.5% reduction) the release of IL-6 by MSCs. SteLL also reduced the levels of this cytokine in culture supernatant. In conclusion, ApuL and SteLL showed potential to reduce the viability of leukemia cells, as well as immunomodulatory effect on MSCs without being toxic to them. These biological properties can be explored biomedically and biotechnologically in the future.
{"title":"Effects of Lectins from Alpinia purpurata Inflorescence (ApuL) and Schinus terebinthifolia Leaf (SteLL) on Human Leukemic Cell Lines and Mesenchymal Stem Cells","authors":"Jéssica de Santana Brito, Amanda de Oliveira Marinho, L. L. de Siqueira Patriota, W. D. C. Gaião, Diego José Lira Torres, P. Paiva, V. D. de Lorena, C. G. Rodrigues, M. B. da Silva, T. Napoleão","doi":"10.3390/macromol3020018","DOIUrl":"https://doi.org/10.3390/macromol3020018","url":null,"abstract":"Lectins (carbohydrate-binding proteins) are able to distinguish different patterns of glycosylation on cell surfaces. This study investigated the effects of lectins from Alpinia purpurata inflorescence (ApuL) and Schinus terebinthifolia leaf (SteLL) on the viability of human leukemia cells (K562, chronic myeloid leukemia; JURKAT, acute lymphoblastic leukemia) and mesenchymal stem cells (MSCs) from human umbilical cords. In addition, possible immunomodulatory effects of ApuL and SteLL on MSCs were assessed by determining cytokine levels in cultures. ApuL reduced the viability of JURKAT cells (IC50: 12.5 μg/mL), inducing both apoptosis and necrosis. For K562 cells, ApuL at 50 µg/mL caused a decrease in viability, but of only 8.8%. Conversely, SteLL exerted a cytotoxic effect on K562 (IC50: 6.0 μg/mL), inducing apoptosis, while it was not cytotoxic to JURKAT. ApuL and SteLL (0.19–100 μg/mL) did not decrease MSCs viability. Treatment with ApuL strongly suppressed (99.5% reduction) the release of IL-6 by MSCs. SteLL also reduced the levels of this cytokine in culture supernatant. In conclusion, ApuL and SteLL showed potential to reduce the viability of leukemia cells, as well as immunomodulatory effect on MSCs without being toxic to them. These biological properties can be explored biomedically and biotechnologically in the future.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83308911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Contessa, Gabriela Silveira da Rosa, C. C. Moraes, J. F. Burkert
The food industry produces an exorbitant amount of solid waste of petrochemical origin as a result of the increase in the development of new products. Natural polymers are an alternative to this theme; however, their development with adequate properties is a challenge. The union of different polymers in the synthesis of packaging is usually carried out to improve these properties. The combination of agar-agar and chitosan biopolymers show particular advantages through hydrogen bonds and electrostatic attraction between oppositely charged groups, presenting a promising source of studies for the synthesis of green packaging. When combined with natural extracts with active properties, these polymers allow an increase in the microbiological stability of foods associated with lower chemical preservative content and greater environmental sustainability.
{"title":"Agar-Agar and Chitosan as Precursors in the Synthesis of Functional Film for Foods: A Review","authors":"C. Contessa, Gabriela Silveira da Rosa, C. C. Moraes, J. F. Burkert","doi":"10.3390/macromol3020017","DOIUrl":"https://doi.org/10.3390/macromol3020017","url":null,"abstract":"The food industry produces an exorbitant amount of solid waste of petrochemical origin as a result of the increase in the development of new products. Natural polymers are an alternative to this theme; however, their development with adequate properties is a challenge. The union of different polymers in the synthesis of packaging is usually carried out to improve these properties. The combination of agar-agar and chitosan biopolymers show particular advantages through hydrogen bonds and electrostatic attraction between oppositely charged groups, presenting a promising source of studies for the synthesis of green packaging. When combined with natural extracts with active properties, these polymers allow an increase in the microbiological stability of foods associated with lower chemical preservative content and greater environmental sustainability.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89656049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Heat-resistant polymers with an intense, visible photoluminescence (PL) functionality are presented. A polybenzoxazole (PBO) containing hexafluoroisopropylidene (HFIP) side groups exhibited an intense purple PL with a quantum yield, ΦPL, of 0.22 (22%), owing to the effectively disturbed concentration quenching (CQ) in the fluorophore units by the bulky HFIP side groups. The chain ends of a wholly cycloaliphatic polyimide (PI), derived from 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and 4,4′-methylenebis(cyclohexylamine) (MBCHA), were modified with conjugated monoamines. The PI derived from 2,3,6,7-naphthalenetetracarboxylic dianhydride (2,3,6,7-NTDA) and MBCHA exhibited a very high glass transition temperature (Tg = 376 °C) and purple fluorescence from the S1(π,π*) state. However, its ΦPL value was lower than expected. A pronounced effect of fluorophore dilution using CBDA on the PL enhancement was observed. This is closely related to the planar structure of the 2,3,6,7-NTDA-based diimide units. By contrast, the counterpart using an 2,3,6,7-NTDA isomer, 1,4,5,8-NTDA, was virtually non-fluorescent, despite its sufficient dilution using CBDA. The PI film obtained using 3,3″,4,4″-p-terphenyltetracarboxylic dianhydride (TPDA) with a non-coplanar structure and MBCHA exhibited an intense blue fluorescence spectrum (ΦPL = 0.26) peaking at 434 nm. The dilution approach using CBDA enhanced its fluorescence up to a high ΦPL value of 0.41. Even when TPDA was combined with an aromatic diamine, 2,2′-bis(trifluoromethyl)benzidine (TFMB), the intense blue fluorescence was observed without charge-transfer fluorescence. A semi-cycloaliphatic PI derived from TFMB and a novel cycloaliphatic tetracarboxylic dianhydride, which was obtained from a hydrogenated trimellitic anhydride derivative and 4,4′-biphenol, was used as another host polymer for 9,10-bis(4-aminophenyl)anthracene (BAPA). The BAPA-incorporating PI film resulted in a significant PL enhancement with a considerably high ΦPL of 0.48. This PI film also had a relatively high Tg (265 °C). A reactive dye, N,N′-bis[4-(4-amino-3-methylbenzyl)-2-methylphenyl]-3,4,9,10-perylenetetracarboxydiimide, was harnessed as a fluorescence probe to explore transamidation between polyimide precursors in solution.
{"title":"Heat-Resistant Polymers with Intense, Visible Photoluminescence Functionality and Fluorescence Probing Application","authors":"M. Hasegawa, Shunichi Horii","doi":"10.3390/macromol3020016","DOIUrl":"https://doi.org/10.3390/macromol3020016","url":null,"abstract":"Heat-resistant polymers with an intense, visible photoluminescence (PL) functionality are presented. A polybenzoxazole (PBO) containing hexafluoroisopropylidene (HFIP) side groups exhibited an intense purple PL with a quantum yield, ΦPL, of 0.22 (22%), owing to the effectively disturbed concentration quenching (CQ) in the fluorophore units by the bulky HFIP side groups. The chain ends of a wholly cycloaliphatic polyimide (PI), derived from 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and 4,4′-methylenebis(cyclohexylamine) (MBCHA), were modified with conjugated monoamines. The PI derived from 2,3,6,7-naphthalenetetracarboxylic dianhydride (2,3,6,7-NTDA) and MBCHA exhibited a very high glass transition temperature (Tg = 376 °C) and purple fluorescence from the S1(π,π*) state. However, its ΦPL value was lower than expected. A pronounced effect of fluorophore dilution using CBDA on the PL enhancement was observed. This is closely related to the planar structure of the 2,3,6,7-NTDA-based diimide units. By contrast, the counterpart using an 2,3,6,7-NTDA isomer, 1,4,5,8-NTDA, was virtually non-fluorescent, despite its sufficient dilution using CBDA. The PI film obtained using 3,3″,4,4″-p-terphenyltetracarboxylic dianhydride (TPDA) with a non-coplanar structure and MBCHA exhibited an intense blue fluorescence spectrum (ΦPL = 0.26) peaking at 434 nm. The dilution approach using CBDA enhanced its fluorescence up to a high ΦPL value of 0.41. Even when TPDA was combined with an aromatic diamine, 2,2′-bis(trifluoromethyl)benzidine (TFMB), the intense blue fluorescence was observed without charge-transfer fluorescence. A semi-cycloaliphatic PI derived from TFMB and a novel cycloaliphatic tetracarboxylic dianhydride, which was obtained from a hydrogenated trimellitic anhydride derivative and 4,4′-biphenol, was used as another host polymer for 9,10-bis(4-aminophenyl)anthracene (BAPA). The BAPA-incorporating PI film resulted in a significant PL enhancement with a considerably high ΦPL of 0.48. This PI film also had a relatively high Tg (265 °C). A reactive dye, N,N′-bis[4-(4-amino-3-methylbenzyl)-2-methylphenyl]-3,4,9,10-perylenetetracarboxydiimide, was harnessed as a fluorescence probe to explore transamidation between polyimide precursors in solution.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89291893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thea Serra, L. Anfossi, Simone Cavalera, Matteo Chiarello, F. Nardo, Valentina Testa, C. Baggiani
The solid-phase polymerization synthesis (SPPS) represents one of the most innovative approaches to the preparation of nano-sized molecularly imprinted polymers. One of its main features consists of the use of a solid support on which the template molecule is covalently grafted. It implies that the imprinting process does not involve the target molecule as is, but, rather, a structural modification of it. It is known that the rationally designed mimic N-(4-chloro-1-hydroxy-2-naphthoylamido)-(L)-phenylalanine (CHNA-Phe) is able to generate, by bulk polymerization, imprinted materials capable of recognizing the mycotoxin Ochratoxin A (OTA). In this work, we wanted to verify whether the CHNA-Phe can be a useful mimic template in the SPPS technique. The binding isotherm were measured in the pH range of 4–8 and the binding affinities for CHNA-Phe and OTA were compared, showing that CHNA-Phe-imprinted nanoMIPs recognize, in buffered water, equally well OTA, and that the overall molecular recognition depends markedly from pH-related ionic interactions between the ligand and the binding site. There results confirm that in the SPPS method, it is possible and convenient to use as mimic templates a molecule whose three-dimensional structure is to some extent different from the target without substantial loss of selectivity or binding affinity.
{"title":"Ochratoxin A-Imprinted nanoMIPs Prepared by Solid Phase Synthesis: Effect of Mimic Template on Binding Properties","authors":"Thea Serra, L. Anfossi, Simone Cavalera, Matteo Chiarello, F. Nardo, Valentina Testa, C. Baggiani","doi":"10.3390/macromol3020015","DOIUrl":"https://doi.org/10.3390/macromol3020015","url":null,"abstract":"The solid-phase polymerization synthesis (SPPS) represents one of the most innovative approaches to the preparation of nano-sized molecularly imprinted polymers. One of its main features consists of the use of a solid support on which the template molecule is covalently grafted. It implies that the imprinting process does not involve the target molecule as is, but, rather, a structural modification of it. It is known that the rationally designed mimic N-(4-chloro-1-hydroxy-2-naphthoylamido)-(L)-phenylalanine (CHNA-Phe) is able to generate, by bulk polymerization, imprinted materials capable of recognizing the mycotoxin Ochratoxin A (OTA). In this work, we wanted to verify whether the CHNA-Phe can be a useful mimic template in the SPPS technique. The binding isotherm were measured in the pH range of 4–8 and the binding affinities for CHNA-Phe and OTA were compared, showing that CHNA-Phe-imprinted nanoMIPs recognize, in buffered water, equally well OTA, and that the overall molecular recognition depends markedly from pH-related ionic interactions between the ligand and the binding site. There results confirm that in the SPPS method, it is possible and convenient to use as mimic templates a molecule whose three-dimensional structure is to some extent different from the target without substantial loss of selectivity or binding affinity.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78747625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Induced pluripotent stem cells (iPSCs) may develop into any form of cell and are being intensively investigated. The influence on iPSCs of nanostructures generated using two-dimensional colloidal arrays was examined in this study. Colloidal arrays were formed using the following procedure. First, core–shell colloids were adsorbed onto a glass substrate using a layer-by-layer method. Second, the colloids were immobilized via thermal fusion. Third, the surface of the colloids was modified by plasma treatment. By adjusting the number density of colloids, cultured iPSCs were easily detached from the substrate without manual cell scraping. In addition to planar culture, cell aggregation of iPSCs attached to the substrate was achieved by combining hydrophilic surface patterning on the colloidal array. Multilayered cell aggregates with approximately four layers were able be cultured. These findings imply that colloidal arrays might be an effective tool for controlling the strength of cell adhesion.
{"title":"Easy Cell Detachment and Spheroid Formation of Induced Pluripotent Stem Cells Using Two-Dimensional Colloidal Arrays","authors":"Goshi Kuno, A. Matsumoto","doi":"10.3390/macromol3020014","DOIUrl":"https://doi.org/10.3390/macromol3020014","url":null,"abstract":"Induced pluripotent stem cells (iPSCs) may develop into any form of cell and are being intensively investigated. The influence on iPSCs of nanostructures generated using two-dimensional colloidal arrays was examined in this study. Colloidal arrays were formed using the following procedure. First, core–shell colloids were adsorbed onto a glass substrate using a layer-by-layer method. Second, the colloids were immobilized via thermal fusion. Third, the surface of the colloids was modified by plasma treatment. By adjusting the number density of colloids, cultured iPSCs were easily detached from the substrate without manual cell scraping. In addition to planar culture, cell aggregation of iPSCs attached to the substrate was achieved by combining hydrophilic surface patterning on the colloidal array. Multilayered cell aggregates with approximately four layers were able be cultured. These findings imply that colloidal arrays might be an effective tool for controlling the strength of cell adhesion.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79290572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the formation processes of holographic gratings in polymers as a function of material composition and processing is important for the development of new materials for holography and its associated applications. Among the processing-related factors that affect grating formation in volume holographic recording material, pre-exposure, prebaking and dark storage, as well as the associated variations in layer thickness and composition, are usually underestimated. This study highlights the influence and interaction of these factors and shows that they should not be neglected. This is of particular importance for samples with a free surface. Here, one such epoxy-based free-surface material is investigated. To determine the influence of prebaking on the holographic grating formation, as well as on the achieved refractive index contrast, angular resolved analysis of volume holographic phase gratings is applied through point-by-point scanning of the local material response. Grating characteristics are determined by comparison with simulations based on rigorous coupled wave theory. Thus, the optimal dose for prebaking can be determined, as well as the optimal exposure time, depending on the dose. The influence of dark storage on the material response is investigated over a period of 12 weeks and shows a strong dependence on the deposited energy density.
{"title":"The Interplay of Processing-Related Influences on the Formation of Volume Holographic Gratings in a Free-Surface Epoxy-Based Recording Material","authors":"Tina Sabel-Grau","doi":"10.3390/macromol3020013","DOIUrl":"https://doi.org/10.3390/macromol3020013","url":null,"abstract":"Understanding the formation processes of holographic gratings in polymers as a function of material composition and processing is important for the development of new materials for holography and its associated applications. Among the processing-related factors that affect grating formation in volume holographic recording material, pre-exposure, prebaking and dark storage, as well as the associated variations in layer thickness and composition, are usually underestimated. This study highlights the influence and interaction of these factors and shows that they should not be neglected. This is of particular importance for samples with a free surface. Here, one such epoxy-based free-surface material is investigated. To determine the influence of prebaking on the holographic grating formation, as well as on the achieved refractive index contrast, angular resolved analysis of volume holographic phase gratings is applied through point-by-point scanning of the local material response. Grating characteristics are determined by comparison with simulations based on rigorous coupled wave theory. Thus, the optimal dose for prebaking can be determined, as well as the optimal exposure time, depending on the dose. The influence of dark storage on the material response is investigated over a period of 12 weeks and shows a strong dependence on the deposited energy density.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90070413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. R. Ferreira, Marilia C. Farina, Anderson Maia, Rondes F. S. Torin
This work evaluated the synergistic effect of citronella essential oil (Ct) and montmorillonite (MMT) (called hybrid compound) incorporated in Poly(lactic acid) (PLA) films at different concentrations (3, 10, 15, and 20 wt%). PLA films were characterized using X-ray diffraction, SEM, TGA, and DSC considering their mechanical properties and essential oil migration. XRD analysis showed the effective interaction between MMT and oil. Thermal analysis, SEM, and mechanical tests were essential to understand the saturation point of the PLA composites. Samples with 15% and 20% of Ct showed a crystallinity reduction of 0.5% compared to samples with 3% and 10% of Ct. PLA/MMT–Ct showed a reduction in tensile strength of the order of 16 and 24, correlated to 15% and 20% of the Ct content, respectively, compared to PLA/MMT–Ct3%. Migration tests showed fast oil delivery correlated with high oil concentration, as evidenced using the PLA/MMT–Ct20% sample results, which showed an estimated release of 50% in the first 150 h due to system saturation, and the remaining being released in the last 350 h. Therefore, the migration tests provide an effective Ct concentration range promising for application with active packaging due to the intrinsic antimicrobial properties of Ct.
{"title":"PLA Films Containing Montmorillonite Nanoclay–Citronella Essential Oil Hybrids for Potential Active Film Formulation","authors":"R. R. Ferreira, Marilia C. Farina, Anderson Maia, Rondes F. S. Torin","doi":"10.3390/macromol3020012","DOIUrl":"https://doi.org/10.3390/macromol3020012","url":null,"abstract":"This work evaluated the synergistic effect of citronella essential oil (Ct) and montmorillonite (MMT) (called hybrid compound) incorporated in Poly(lactic acid) (PLA) films at different concentrations (3, 10, 15, and 20 wt%). PLA films were characterized using X-ray diffraction, SEM, TGA, and DSC considering their mechanical properties and essential oil migration. XRD analysis showed the effective interaction between MMT and oil. Thermal analysis, SEM, and mechanical tests were essential to understand the saturation point of the PLA composites. Samples with 15% and 20% of Ct showed a crystallinity reduction of 0.5% compared to samples with 3% and 10% of Ct. PLA/MMT–Ct showed a reduction in tensile strength of the order of 16 and 24, correlated to 15% and 20% of the Ct content, respectively, compared to PLA/MMT–Ct3%. Migration tests showed fast oil delivery correlated with high oil concentration, as evidenced using the PLA/MMT–Ct20% sample results, which showed an estimated release of 50% in the first 150 h due to system saturation, and the remaining being released in the last 350 h. Therefore, the migration tests provide an effective Ct concentration range promising for application with active packaging due to the intrinsic antimicrobial properties of Ct.","PeriodicalId":18139,"journal":{"name":"Macromol","volume":"40 7 Pt 1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82844813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}