Macromolecular bioscience最新文献

The development of multifunctional scaffolds integrating mechanical robustness and bioactivity is crucial for bone tissue engineering. In this study, chitosan-based scaffolds reinforced with hydroxyapatite (HAP) and potassium sodium niobate (KNN) are fabricated via freeze-drying. Structural characterization confirmed crystalline phase purity, strong interfacial bonding, and uniform elemental distribution without secondary phases. Morphological analysis of the composites revealed interconnected porous networks with an average pore size of 95 ± 8 nm and porosity of 77%. Mechanical testing depicted marked improvement, with the Young's modulus of the composite reaching 4.14 MPa, nearly double that of chitosan. Bioactivity assays demonstrated dense apatite growth after 12 days in simulated body fluid, with a Ca/P ratio of 1.66, close to stoichiometric HAP. Swelling and enzymatic degradation studies indicated reduced fluid uptake and slower degradation of 11.9 ± 0.4% over 24 days for the composite, compared to pure chitosan and single-phase scaffolds, thereby confirming enhanced stability. Antioxidant analysis using an in vitro assay reported 48.6 ± 0.5% radical scavenging for the composite, notably higher than 36 ± 0.6% observed for chitosan, while protein adsorption increased to 20–27 µg/mL compared to 9 µg/mL. MG-63 osteoblasts exhibited > 90% viability at day 1 and sustained growth through day 5 with spreading and adhesion. These results highlight HAP-KNN reinforced chitosan scaffolds as promising multifunctional platforms for orthopedic applications.

Effective control of large and deep wounds with incompressible bleeding is essential for pre-hospital first aid. The development of rapid and effective emergency hemostatic materials could reduce the amount of blood loss, promote wound healing, and improve the survival rate. In this study, a carboxymethyl chitosan/ Panax notoginseng polysaccharide (CMCS&PNP) sponge with a layered porous structure was developed, which has high hemostatic and antibacterial effects. The unique bark-like layered porous structure was prepared by the rapid freezing method, which enabled CMCS&PNP to quickly adsorb the water from the bottom of the sponge to the upper layer (the water absorption rate within 3 min could reach 256.83 ± 2.04%). The smaller pores between the two layers allow red blood cells and fibrin to be trapped on the surface of the bottom of the sponge, thereby concentrating the tangible components of the blood and speeding up clotting. The pro-coagulant activity, pro-healing ability, and antibacterial properties of CMCS&PNP were confirmed by in vivo and in vitro experiments. This study not only developed a new composite sponge with high efficiency in hemostasis but also promoted healing. In addition, we also studied the effect of the layered porous structure prepared by rapid freezing on hemostasis and wound healing, providing a new perspective for the development of a composite hemostatic sponge.

The healing of skin wounds is a complex process, the outcome of which is determined by a combination of factors. Adverse factors, such as infection, chronic inflammatory infiltration, and poor vascularity, can impede the healing process, significantly reducing the quality of life. The primary method of promoting wound healing is pharmacotherapy; however, pharmacotherapy alone has several disadvantages, including poor release control, a short half-life, and low bioavailability. Therefore, designing materials with well-controlled release properties and increased bioavailability is important. In this study, ginsenoside Rg1 was incorporated into a photo-crosslinking (LAP/UV) and chemical cross-linking (EDC-mediated amide bond formation) hydrogel synthesized from hyaluronic acid methacrylamide and silk fibroin to enhance drug activity. The resulting composite hydrogel has good hydrophilicity, mechanical properties, and stability, enabling the slow release of Rg1 for up to 14 days. In addition, in vitro experiments revealed that the composite hydrogel exhibits good biocompatibility (Cell viability > 90%) and promotes angiogenesis and maturation. In subsequent in vivo experiments, the composite hydrogel showed a good ability to promote vascular regeneration (p < 0.0001) and collagen deposition. Finally, Western blotting and qPCR analysis of rat tissues showed that the drug-loaded composite hydrogel group possessed anti-inflammatory and tissue healing abilities. This suggests that the composite hydrogel developed shows great promise in promoting wound healing.

Hydroxyapatite (HAP) composite coatings have emerged as promising candidates in orthopaedic implantology because they promote osteoconduction and facilitate biological integration. This study investigates the effect of cerium (Ce) incorporation at graded concentrations (0.3–0.8 wt.%) on the microstructural, interfacial, and functional properties of hydroxyapatite/carbon nanotube (HAP/CNT) hybrid nanocomposite coatings fabricated via electrochemical deposition mode. Among the developed systems, the HAP-CNT-0.8Ce formulation demonstrated outstanding performance, exhibiting a Ca/P atomic ratio of 1.56, a water contact angle of 40.8° with surface roughness of 0.66 µm, a maximum hardness of 354 HV, an adhesion strength of 52 MPa, and pronounced antibacterial activity, reducing the viability of E. coli and S. aureus to ∼67.5%, and ∼45.6%, respectively. The bioactivity analysis revealed that HAP-CNT-Ce coatings exhibited sustained ion release–mediated apatite nucleation in simulated body fluid, leading to enhanced HAP crystallisation and superior biomineralization potential. The HAP-CNT-0.8Ce variant, characterized by a nanoscale crystallite size of 20 ± 2.1 nm and a crystallinity degree of 44.45%, exhibited a refined grain architecture that markedly enhanced its mechanical and biological performance, thereby affirming its structural robustness and interfacial integrity. Altogether, the integration of multifunctional attributes, including mechanical robustness, cellular compatibility, and enhanced osseointegration, positions this advanced coating as a highly viable solution for next-generation orthopaedic implants and bone regeneration platforms in the context of translational biomedical engineering.

Tympanic membrane perforation (TMP) often leads to hearing loss and requires effective repair strategies. However, existing surgical options are invasive and lack ideal biomaterials for scaffold-based healing. Herein, we present a custom-engineered mechano-acoustic responsive hydrogel incorporating bFGF-loaded sodium alginate microspheres, designed for controlled drug release and tissue regeneration under dual stimulation: vibrational simulation and low-frequency acoustic waves (generated by radio devices) — representing its first transition from in vitro characterization to in vivo regenerative application. This polymer-based scaffold exhibits robust adhesion, biocompatibility, and mechanoresponsive release behavior. A rat acute TMP model was employed to evaluate the hydrogel's therapeutic efficacy. Compared with control and blank hydrogel groups, the bFGF-loaded mechanoresponsive hydrogel (SGM) noticeably accelerated tympanic membrane closure, reduced local inflammation, and enhanced early auditory recovery, as confirmed by otoscopic inspection, ABR tests, histological staining, and TEM imaging. Our findings demonstrate that the SGM hydrogel effectively promotes functional tissue regeneration and early hearing restoration in vivo. This work highlights the potential of polymer-based, stimuli-responsive biomaterials in advancing minimally invasive strategies for TMP treatment and offers valuable insights for future tissue engineering applications in otolaryngology.

Stimuli-responsive polymeric fibers have emerged as an indispensable material for numerous biomedical applications. Strategies to conjugate functional molecules with high specificity onto these nanofibers are vital to tailor these materials for specific applications. When the functionalization is reversible, these materials can serve as a ‘catch and release’ platform, which widens their applicability. Herein, polymeric fibers with an average diameter of about 237 ± 44 nm, amenable to reversible conjugation, are fabricated using electrospinning. The thiol-disulfide exchange reaction is employed to functionalize the electrospun fibers with thiol-containing functional molecules ranging from fluorescent dyes to bioactive ligands for protein immobilization. It is demonstrated that the linked (bio)molecules can be efficiently released in the presence of a thiol-containing reducing agent. Specifically, pyridyl disulfide (PDS)-containing copolymers are synthesized using a thiol-reactive PDS-based monomer, methyl methacrylate, and poly(ethylene glycol) methacrylate, where the monomers enable thiol-based specific functionalization, stable fiber formation, and anti-biofouling characteristics, respectively. After demonstrating efficient functionalization and release using fluorescent dyes and bioactive ligands, these fibers are conjugated with a thiol-containing cationic antibacterial peptide. It is demonstrated that the released peptide preserves its antibacterial activity against planktonic bacteria as well as biofilms. One can envision that the facile fabrication, efficient functionalization, and on-demand release attribute of these reversibly functionalizable polymeric fibers disclosed here would be attractive platforms for a wide range of biomedical applications.

The implant-soft tissue interface is critical for successful integration. However, developing multifunctional coatings that combine antibacterial action, strong interfacial adhesion, and regenerative capacity remains a significant challenge. This study presents a novel hydrogel coating for surface modification of phthalazinone-naphthalene-based Poly(phthalazinone ether ketone) (PPEK) implants. The coating consists of an MgO nanoparticle-embedded, photocrosslinked gelatin/chitosan hydrogel functionalized with NHS groups. XPS and ¹H NMR analyses confirmed that NHS groups mediate covalent bonding. This bonding occurs with amine moieties on both plasma-activated PPEK implants and soft tissues, substantially improving interfacial adhesion. The coating demonstrated dual functionality: broad-spectrum antibacterial activity and sustained Mg²⁺ release. The released Mg²⁺ exhibited multiphase bioeffects. These bioeffects include enhanced migration of L929 fibroblasts, HUVECs, and HaCaT keratinocytes; stimulated HUVEC tubulogenesis; and upregulated extracellular matrix synthesis. Both in vitro and in vivo assessments revealed synergistic acceleration of collagen deposition and angiogenesis. This synergy facilitates rapid soft tissue regeneration. Subcutaneous implantation models demonstrated dual integration mechanisms: NHS-driven covalent adhesion and Mg²⁺-mediated bioactive remodeling via cellular activation. These results position the MgO-integrated nanocomposite hydrogel as a multifunctional therapeutic coating. It simultaneously addresses microbial resistance, interfacial stability, and tissue regeneration for optimized implant-soft tissue integration. The design paradigm merges physicochemical bonding with ion-modulated bioactivity. This approach offers a strategic solution for complex interface engineering in biomedical implants.

Hydrogen sulfide (H₂S) is an endogenous gasotransmitter that possesses multiple pathological and physiological functions, including anti-inflammation, anti-thrombosis, anti-calcification, inhibition of intimal hyperplasia, and promotion of angiogenesis. Therefore, we aim to design an H₂S-releasing resorbable synthetic graft that utilizes the therapeutic benefits of the H₂S to modulate the graft regeneration. To ease fabrication of the H₂S-releasing graft, we have designed a pair of functional polyesters that are electrospinnable and photocurable to form an elastic fibrous conduit. The conduit bears free thiol groups that are conjugated with a methacrylated H₂S donor through thiol-ene click chemistry to form an H₂S-releasing graft. The graft can sustainably release H₂S over ∼12 days in vitro. Differing from prior designs, the H₂S-releasing graft simultaneously possesses key features of a robust elasticity, and suitable mechanical properties, degradation rate and porosity. At the proof-of-concept stage, we examined the H₂S stimulation on endothelial cell growth using the graft with a low H₂S releasing rate. The results demonstrated that the graft with sustained H₂S release could significantly promote endothelial cell growth in vitro. This work paved the way for in vivo evaluation of the H₂S-releasing graft.