Macromolecular Research最新文献

The transition from two-dimensional to three-dimensional cell cultures has transformed the understanding of cell physiology and cell–matrix interactions. Extracellular matrix (ECM) mimics tend to fall into either the natural or synthetic categories. Naturally occurring ECM mimics, such as collagen and gelatin, have superior bioactive properties but typically lack tuneability. Conversely, synthetic ECM mimics are highly defined but even with modifications, can lack the bioactivity of natural proteins. Therefore, to take advantage of the potential of both natural and synthetic ECM mimics, a biohybrid ionically crosslinked gelatin hydrogel was synthesised. This was achieved by utilising free amine groups along the gelatin backbone as the basis for a reversible addition − fragmentation chain-transfer (RAFT) reaction. The resulting polymers had tuneable stiffness and enhanced solubility compared to gelatin. The biohybrid gel also showed good biocompatibility, with MCF-7 cells forming larger spheroids when encapsulated within the biohybrid gel when compared to an unfunctionalized polyethylene-glycol (PEG) gel. Furthermore, due to the ionic crosslinking in the biohybrid gel, spheroids can be retrieved by digesting the matrix using 10 × phosphate-buffered saline (PBS). Retrieved cells were shown to be viable which allows for the potential of downstream analysis. Thus, this study highlights the potential of hybrid gelatin–PEG hydrogels for 3D cell culture.

Graphical abstract

The biohybrid gelatin (Gelatin-SPMA) is crosslinked with a positively charged polymer (PEG-MAETMA) to form a gel within seconds. MCF-7 cells survived encapsulation and formed spheroids over 7 days. 10x phosphate buffered saline (PBS) was then used to digest the hydrogel, allowing for the recovery of encapsulated spheroids.

Traumatic injuries typically lead to severe wounds which are accompanied by excessive hemorrhage. Although various hemostatic wound dressings have been developed, there is an ongoing need for advanced materials that combine both hemostatic and therapeutic abilities for effective wound management. Cryogels, an emerging class of wound-dressing materials, have garnered significant attention because of their enhanced mechanical properties, blood and wound exudates absorption abilities that improve the hemoconcentration, and substantial porosities that facilitate the infiltration of host cells and tissues, all of which contribute to improved wound healing. Growing evidence has demonstrated that oxygen-generating materials promote wound healing, including angiogenesis, by inducing hyperoxic oxidative stress. Here, a new type of oxygen-generating cryogel (Oxycryogel) is fabricated by lyophilizing oxygen-generating hydrogels formed by a calcium peroxide (CaO₂)-mediated crosslinking reaction, which resulted in interconnected macroporous structures with reinforced mechanical properties compared to that of hydrogel formulations. The Oxycryogels developed in this study demonstrate superior blood absorption capabilities and calcium ion (Ca²⁺) production by CaO₂ decomposition. Additionally, blood clot formation is improved through hemoconcentration and Ca²⁺-mediated coagulation cascades in vitro. Furthermore, the oxygen-releasing kinetics are modulated by adjusting the CaO₂ concentration and are further promoted using a catalase solution. The Oxycryogels provide transient hyperoxic conditions in vitro and in vivo, facilitating wound healing, such as angiogenesis and wound closure through the synergistic effects of porosity, hemostatic ability, and hyperoxic oxidative stress in vivo. In conclusion, the Oxycryogels developed here have great potential as advanced oxygen-delivery and hemostatic materials for wound healing and management.

Graphical abstract

Oxygen-generating gelatin-based cryogels (Oxycryogels), a new type of wound dressing integrating hemostasis and wound healing, are developed through lyophilization and calcium peroxide (CaO₂)-mediated reactions. CaO₂ provides oxygen for angiogenesis and calcium ions for blood coagulation, while the strong blood absorption of Oxycryogels enhances hemoconcentration, collectively facilitating effective skin wound healing.

The effect of surface morphology on drug release in temperature sensitive poly (N-isopropylacrylamide) (PNIPAAm) hydrogel film was studied. To increase the surface area of hydrogel film for the susceptible responsibility to the external stimulus, a convex structured biomimetic moth eye patterned (MEP) hydrogel film was fabricated using porous honeycomb-patterned polymer film as a template prepared by the breath figure (BF) method. For the comparison, a non-patterned flat hydrogel film was also fabricated by a similar method on the flat template not porous polymer film. In addition, a small amount of graphene oxide (GO) was added in the PNIPAAm hydrogel film to inhibit the drug (rhodamine B, RhB) release by the simple diffusion not by stimuli-responsive release by forming hydrogen bonds with loaded RhB. The hydrogel film with MEP pattern was more sensitive to the temperature change around the lower critical solution temperature (LCST) of 37 °C for the release of RhB. The result seems to be due to the high ratio of shrinking-swelling in the MEP patterned film.

Graphical abstract

Temperature responsive surface morphology change, and induced rhodamine B release by the change in patterned and nonpatterned hydrogel film.

Infected bone defects pose a significant challenge in regenerative medicine, hindering successful bone tissue repair. The inherent electrical properties of native bone tissue offer a promising avenue for developing novel therapeutic strategies. Electroactive biomaterials, designed to mimic these properties, have emerged as potential tools for promoting bone regeneration and combating infection. This review explores the intricate relationship between electroactivity and bone healing, focusing on the capacity of these biomaterials to recapitulate the electrical cues essential for osteogenesis. We provide a comprehensive overview of materials known to stimulate bone regeneration in the context of infection, including conductive polymers, piezoelectric ceramics, and bioactive glasses. Furthermore, we delve into the specific mechanisms by which electroactive biomaterials exert their antibacterial and anti-inflammatory effects, highlighting the role of electrical stimulation in modulating cellular responses and combating microbial colonization. While previous research has often addressed bone regeneration and antibacterial action separately, this review emphasizes the synergistic potential of dual-functional electroactive biomaterials. By combining regenerative and antimicrobial properties, these advanced biomaterials hold promise for overcoming the complex challenges associated with infected bone defects. This comprehensive analysis of current literature aims to stimulate further research and development in this critical area of biomaterials science.

Graphical Abstract

Electroactive biomaterials are highly promising materials for regenerating infected bone tissue by simultaneously performing both antibacterial and osteogenesis functions. The regulation of immune cells and the promotion of vascularization effectively support these dual functions.

Traditional wound dressing materials, such as gauge, cotton pads, adhesive bandages, etc., are non-occlusive, often incapable of handling high exudates, leading to drying out. Among various dressing materials available, foam dressing has shown better patient compliance and, most importantly, does not cause wound trauma. Synthetic polymers used for dressing foams possess some unfavourable health and environmental issues, when they interact with the human body, leading to hypersensitivity reactions, exposed particles can cause loss of consciousness and even blindness. These adverse outcomes can be averted by the use of natural polymers. Thus, this study focuses on the fabrication and characterization of foam dressing using natural polymers infused with graphene oxide (GO) as a self-healing nanomaterial. For the fabrication, the optimal concentration of polymers and GO have been selected using Quality by Design (QbD) approach. First of all, graphene oxide nanoparticles were prepared using the modified hummer’s method and were characterized using DLS, Raman spectroscopy, FESEM, FTIR, XRD, and TGA/DTA. The synthesis process involved the fabrication of foam dressing using combinations of various natural polymers having wound-healing property and the incorporation of GO into biocompatible polymer matrices. The best combination of polymers was decided based on preliminary characterization tests including absorption rate, fluid retention rate, water vapour transmission rate, and porosity test. Chitosan and sodium alginate combination was found to exhibit superior characteristics and was selected for optimization. It was further characterized to assess its morphological, mechanical, degradation, and antimicrobial studies. In conclusion, the optimized foam demonstrated superior properties, presenting a promising and safer alternative to synthetic polymer-based materials.

Graphical abstract

The fabrication and characterization of a self-healing foam dressing (FD) were carried out using natural polymers (chitosan, pectin, sodium alginate, and gelatin) infused with graphene oxide. Graphene oxide nanoparticles were synthesized using a modified Hummer’s method and characterized using DLS, Raman spectroscopy, FESEM, FTIR, XRD, and TGA/DTA. FDs were optimized using the Quality by Design (QbD) approach, ensuring superior absorption, fluid retention, water vapor transmission, and porosity. The optimized dressing exhibited excellent morphological, mechanical, degradation, and antimicrobial properties, making it a promising and biocompatible alternative to synthetic polymer-based wound dressings.

With the development of nanodelivery systems, significant breakthroughs have been achieved in tumor diagnosis and treatment. These systems effectively address the limitations of traditional anti-tumor drugs, such as poor solubility, lack of targeting, and systemic toxicity, which often lead to suboptimal therapeutic outcomes. In particular, environment-responsive drug carriers, triggered by the unique tumor microenvironment, enable precise and controllable drug release at tumor sites, improving the efficiency of drug accumulation in tumors and reducing off-target distribution, thus minimizing unnecessary side effect on normal tissues. Among various nanocarriers, porous nanocarriers have distinct advantages, including high surface area, large drug loading capacity, tunable pore size, and easy surface modification. These features made them have unique advantages in the field of drug delivery and tumor diagnosis and therapy. Combination therapy designs using porous nanocarriers can effectively overcome the limitation of monotherapy, leading to synergistic effect in tumor treatment. Especially, a tumor multi-modal combination therapy strategy designed by porous nanocarriers can effectively overcome the limitation of single therapy, and thus generate a cascaded amplification effect in tumor therapy. This paper reviews and summarizes recent advances in porous nanocarriers for tumor diagnosis and therapy discusses their advantages and challenges, and provides insights for the development of more intelligent and diversified composite drug systems based on porous carriers.

Graphical abstract

Classification of porous materials

Chronic wounds in the skin require new hydrogel formulations that can heal regenerating damaged tissue and release therapeutic molecules that benefit healing and higher swelling capacities. In a previous study, synthetic molybdenum complexes based on molybdenum (Mo), terephthalic acid (BDC), and bis(2-hydroxyethyl) terephthalate (BHET) demonstrated that they stimulate fibroblast in vitro viability, representing potential candidates to be applied as fillers in collagen hydrogels for tissue engineering. Continuing this work, new composite hydrogels based on collagen and these molybdenum complexes varied their mass concentration (1 or 4 mg). The objective was to enhance collagen’s rheological and antimicrobial properties without altering biocompatibility. These materials were characterized using physicochemical techniques, including wide angle x-ray scattering (WAXS), scanning electron microscope (SEM), attenuated total reflection Fourier-transform infrared (ATR-FTIR), thermogravimetric analysis (TGA), rheology, and crosslinking assessed by ninhydrin assay. In addition, the in vitro biocompatibility of dermis porcine fibroblast and human monocytes was tested growing on the hydrogels. The hydrogels do not present cytotoxic effects on the cells tested and show good safety in topical applications because they are biocompatible materials with antibacterial properties. Coenzyme Q-10 can control chronic inflammation, helping tissue healing. Thus, Q-10 was encapsulated in situ in the hydrogel synthesis, and their release kinetic profiles were obtained. It was found that a significant amount of Mo-complexes (4 mg) in the collagen matrix generated the best biological and physicochemical properties. Indeed, the hydrogel with 4 mg of the molybdenum complex BHET-Mo (CBH4) shows a 100% release of Q10 with a sustainable behavior, large storage (G’ = 240 kPa), and loss modulus (G’’ = 70 kPa) and swelling capacity (41 739%). In comparison, the hydrogel with 4 mg of the molybdenum complex BDC-Mo (CBD4) should be considered for skin regeneration since it dramatically stimulates the metabolic activity of fibroblasts (186%) and monocytes (240%) with a relative antimicrobial activity against E. Coli of 100% compared with ampicillin (positive control).

Graphical abstract

Collagen-Mo-complexes hydrogels with outstanding results for in vitro biocompatibility (CBD4) and drug release (CBH4).

We propose an efficient method for fabricating superamphiphobic surfaces with hierarchical micro/nano-structured morphologies on microhoodoo structures that exhibit high liquid impact resistance. The proposed method combines optical microscopy, photolithography, replica molding, and spray coating of polydimethylsiloxane (PDMS)/silica nanoparticle (SiNP) solutions. We systematically investigate key parameters influencing the water and hexadecane repellency of these surfaces, including (i) the center-to-center distance between PDMS microhoodoo structures, (ii) the PDMS-to-SiNP mixing ratio, and (iii) the spray volume. Notably, optimizing the spray volume within a critical range improves the uniformity of the hierarchical surface texture, stabilizes the Cassie–Baxter state, and facilitates liquid bounce. This innovative approach provides valuable insights into the design of superamphiphobic surfaces, resulting in practical applications such as water- and oil-resistant, self-cleaning, anti-icing, and antifouling surfaces.

Graphical abstract

Efficient fabrication of superamphiphobic surfaces with hierarchical micro/nano-structures on microhoodoo structures, achieved through optical microscopy, photolithography, replica molding, and spray coating of PDMS/SiNP solutions. Key factors influencing liquid repellency—such as microhoodoo spacing, PDMS/SiNP ratio, and spray volume—are systematically explored. Optimizing spray volume enhances surface texture uniformity, stabilizes the Cassie–Baxter state, and promotes liquid bounce, leading to practical applications in self-cleaning, anti-icing, and antifouling surfaces.

Despite rapid advancements in the field of perovskite light-emitting diodes (Pe-LEDs), research on polymer hole transport materials (HTMs), a key component of these devices, remains limited. In this study, we developed two new polymer HTMs by substituting the sec-butyl group in the triphenylamine moiety of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB) with either an SCH₃ or OCH₃ group, resulting in OctSMe or OctOMe, respectively. The optical and electrical properties of these new HTMs were thoroughly characterized by various methods. When incorporated into green Pe-LED devices, the new HTMs achieved over 1.6 times higher luminance and a 10–20% reduction in efficiency roll-off compared to the reference TFB, attributed to smoother hole injection and improved energy-level alignment. These enhancements in device performance were further supported by hole-only device experiments and time-resolved photoluminescence analysis. Additionally, devices with the new HTMs demonstrated longer lifetimes than those with TFB, underscoring their potential as effective alternatives in Pe-LED applications.

Graphic Abstract

We developed two new polymer HTMs, OctSMe and OctOMe, by replacing the sec-butyl group in TFB with SCH₃ or OCH₃. In green Pe-LEDs, these HTMs achieved over 1.6 times higher luminance and a 10–20% reduction in efficiency roll-off compared to TFB, due to improved hole injection and energy alignment. Hole-only device tests and time-resolved photoluminescence analysis supported these gains, along with longer lifetimes, suggesting potential as TFB alternatives.