Journal of Materials Science: Materials in Medicine最新文献

The skin, the largest organ of the human body, plays a crucial role in maintaining homeostasis and protecting against external influences. Although it possesses remarkable self-healing capabilities, severe or chronic injuries often necessitate external intervention. In this context, wound management and targeted drug delivery are central areas of biomedical research, where the development of smart biomaterials and the concept of smart wound dressings have revolutionized treatment strategies. Among the various biomaterials, polysaccharide-based wound dressings—particularly dextran-based hydrogels—have gained growing attention due to their excellent biocompatibility, biodegradability, non-toxicity, and clinical safety. Dextran hydrogels exhibit exceptional properties, including high water retention, tunable mechanical strength, and responsiveness to various external stimuli, making them ideally suited for advanced medical applications. This review provides a comprehensive overview of stimuli-responsive polysaccharide hydrogels, with a focus on dextran-based systems. It begins with a discussion of skin structure and function, wound healing mechanisms, and the limitations of chronic and diabetic wounds, highlighting the need for advanced biomaterials. The review then summarizes advances in the design of dextran-based hydrogels, focusing on stimulus responsiveness mechanisms, manufacturing strategies, and crosslinking techniques. Particular attention is paid to their biomedical applications in wound healing and drug delivery, emphasizing mechanisms for controlled release, antimicrobial activity, and tissue regeneration. The review concludes with critical insights into current challenges and future directions for the clinical application of dextran-based hydrogels.

Graphical Abstract

Guided bone regeneration (GBR) is a critical regenerative strategy for repairing periodontal tissues and craniofacial bone defects. It can establish space to prevent undesirable soft tissue invasion and improve bone regeneration. However, commercially available GBR membranes have some disadvantages in terms of biocompatibility and antibacterial efficacy. Hence, we prepared a polycaprolactone (PCL) membrane by electrospinning and then in situ synthesized vancomycin-assisted zeolitic imidazolate framework-8 (Van-ZIF-8) nanoparticles on its surface. With the formation of Van-ZIF-8, the mechanical properties of the PCL membrane were significantly enhanced. Moreover, the release rates of Van and zinc ions (Zn²⁺) showed pH responsiveness. In an acidic environment (pH 5.4), the fast hydrolysis of Van-ZIF-8 led to the rapid release of Van and Zn²⁺. The PCL/Van-ZIF-8 membrane exhibited enhanced antibacterial activity against both aerobic and anaerobic bacteria, including Staphylococcus aureus, Escherichia coli, Porphyromonas gingivalis, and Streptococcus mutans, through the hydrolysis of Van-ZIF-8 nanoparticles. Furthermore, the in vitro results for MC3T3-E1 and L929 cells, including cell viability, alkaline phosphatase activity, mineralization level, collagen secretion, gene expression, and fluorescence staining, demonstrated that the PCL/Van-ZIF-8 membrane possessed excellent osteoinductive capacity and could act as an ideal physical barrier to fibroblast growth.

Graphical Abstract

Schematic illustration of the PCL/Van-Zif-8 electrospinning membrane fabrication and its promotion of mechanical, osteogenesis, and antibacterial properties.

Purpose

The review provides an in-depth analysis of various factors that affect the long-term success of implants and scrutinizes all available techniques for dental implant modifications, along with their advantages and limitations. Along with established and proposed strategies, newer trends such as responsive coatings, ‘omics’ and AI-based possibilities for translating research into clinical settings are discussed.

Methods

The available scientific literature on dental implants, causes for their failures, and possible surface modification techniques was collected and analyzed. Strategies to prevent implant failures are presented as a comprehensive, structured review.

Results

A literature review of scientific research papers published over the last decade clearly indicates that surface modification of dental implants is critical for ensuring long-term success. Strategies aimed at surface changes consider the intrinsic antibacterial activity, surface texture, and geometry of the implant material. In both healthy and compromised patients, bio-functionalized surfaces can improve osseointegration and reduce peri-implantitis, boosting the success of dental implants.

Conclusions

Dental implants, while promising, face hurdles that hinder their long-term success. Modifying implants through physical, chemical, or mechanical methods could potentially address these challenges. These techniques would require clinical validation before being fully integrated into clinical practice. Moreover, crucial factors such as immune response and in vivo testing are often overlooked.

Tissue adhesives are regularly used for wound healing, bleeding control and sealing internal organ leakages. However, currently available tissue adhesives are often cytotoxic. Polycations containing primary amines are generally known to induce cytotoxicity. Complex coacervates, composed of oppositely charged polyelectrolytes, may offer a biocompatible alternative. In this study, primary amines of polyallylamine hydrochloride (pAH) were reacted with glycidyltrimethylammonium chloride (GTMAC) following an epoxide ring nucleophilic substitution to obtain pAH with quaternary ammonium pendant groups (q-pAH). These polycations were combined with negatively charged polysulfopropyl methacrylate (pSPMA) to form complex coacervates. The biocompatibility of the individual polyelectrolytes and resulting complex coacervates was studied using A549 cells through Live/Dead, MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) and LDH (lactate dehydrogenase) assays. Additionally, adhesion to porcine tissues was evaluated. Quaternization of pAH strongly reduced the critical salt concentration (CSC) of the coacervate system, while remaining easy to process and injectable. The cytocompatibility of q-pAH/pSPMA was increased compared to pAH/pSPMA, mainly caused by the reduction of the required salt concentration. Nevertheless, quaternization did not reduce the cytotoxicity of the polycation itself. Complexation with pSPMA effectively reduced cytotoxicity through charge neutralization. Upon direct contact of A549 cells with q-pAH/pSPMA coacervates improved biocompatibility was observed compared to pAH/pSPMA, which could not be fully attributed to effects of reduced salt levels. Both coacervates formed stable, gel-like patches upon the salt switch and these adhered to various tissues. Reduction of complex coacervate cytotoxicity by polycation quaternization can be included in future designs of medical adhesives.

Graphical Abstract

Orthodontic therapy utilizing fixed equipment frequently results in heightened plaque accumulation, which can cause enamel demineralization and periodontal issues. Recent breakthroughs in surface coating technology have brought various antimicrobial techniques designed to diminish bacterial adherence and biofilm formation on orthodontic components. This study thoroughly examines many types of antibacterial coatings, including metallic nanoparticles (such as silver, zinc, and titanium), polymeric layers, carbon-based materials, and bioactive chemicals, emphasizing their modes of action, microbial targets, and therapeutic significance. Silver-based coatings are among the most thoroughly researched due to their continuous ion release and broad-spectrum antibacterial effectiveness. Photocatalytic titanium dioxide and synergistic composite coatings demonstrate promising outcomes under particular activation conditions. The review examines biocompatibility concerns, long-term durability, and the limitations of existing methodologies, while suggesting future research avenues to connect laboratory innovations with clinical applications. The surface modification of orthodontic equipment offers a practical approach to reducing oral health hazards associated with therapy and improving patient outcomes.

Graphical Abstract

Background

Peripheral nerve injury (PNI) poses a significant clinical challenge, often resulting in incomplete functional recovery. This study aimed to develop and evaluate a multifunctional neural guidance conduit combining electrospun PCL/collagen scaffolds with a collagen hydrogel incorporating vinpocetine-loaded chitosan nanoparticles (VINCNPs) and menstrual blood-derived stem cells (MenSCs).

Methods

Electrospun PCL/collagen scaffolds loaded with bioactive collagen hydrogel containing VINCNPs and MenSCs (HYDVINMEN) were prepared. The scaffold-hydrogel constructs were evaluated for physicochemical, mechanical and biological properties in vitro, including cell viability and hemocompatibility. In vivo recovery of motor and sensory function, preservation of muscle, axonal regeneration, and inflammatory and neurotrophic responses were assessed in a rat sciatic nerve transection model.

Results

Nanocarriers achieved a cumulative drug release of 63.37 ± 5.05% at 168 h. Tensile strength analysis showed that PCL/collagen scaffolds had around 3.387 ± 0.434 MPa of ultimate tensile strength. HYDVINMEN group showed better cell viability, swelling and degradation control, and low hemolytic activity. In vivo study of this group showed better sciatic nerve regeneration, functional recovery, reduced muscle atrophy, more myelination, and overall a good modulation in inflammatory cytokines and neurotrophic factors as compared to other experimental groups.

Conclusion

The combinatorial application of VINCNPs and MenSCs in a PCL/collagen scaffold was able to support peripheral nerve regeneration and functional recovery. The bioengineered construct presented an alternative therapeutic strategy to autografts in the treatment of PNI that merits further study for clinical translation.

Graphical Abstract

We review the utilization of chitosan-based nanogels as advanced vehicles for dermal drug delivery. Dermal delivery allows local treatment with a simple application for the patient, while also providing an alternative route that avoids gastrointestinal degradation and first-pass metabolism to help reduce doses and systemic side effects. Nanogels are nanoscale hydrogel networks that preserve the drug-loading capacity and tunable release characteristics of hydrogels, while retaining the colloidal stability of nanoparticles. The addition of chitosan into nanogels provides bioadhesive and permeability-enhancing characteristics; for example, chitosan’s positive charge promotes adhesion to negatively charged skin and can transiently open tight junctions to improve uptake of drugs. Chitosan nanogels exhibit higher drug encapsulation efficiency and more controlled release than conventional topical or bulk gels, and improved penetration into biological membranes due to their small size and surface charge. Chitosan nanogels can be prepared by various methods, including via ionic gelation (electrostatic crosslinking), emulsification (with emulsion polymerization), self-assembly, and radical (covalent) polymerization. These systems have been investigated in dermatology, skin care, cosmetics, and dermal cancer therapy. Overall, chitosan nanogels represent a unique and versatile platform in which mucoadhesion, biocompatibility, and permeation enhancement can collectively improve the efficacy and safety of topical and transdermal therapies.

Orthopedic osteosarcomas and metastatic lesions can be difficult to treat with systemically delivered chemotherapy agents alone. Following removal of the primary tumor, implantation of cement to fill the lesion is often done to stabilize weight-bearing bones. One of the commonly used treatments to address osteosarcoma is systemic delivery of doxorubicin. Therefore, research on the incorporation and release of efficacious doxorubicin for local delivery from cement is important. Poly(methyl methacrylate) (PMMA)-based bone cements are the gold standard in orthopedics but have inherent disadvantages. Efforts to overcome some of these deficiencies led to the development of a novel silorane-based biomaterial (SBB). This work evaluated the ability of both PMMA and SBB to incorporate and release efficacious doxorubicin. PMMA-released doxorubicin showed reduced chemotherapeutic efficacy in vitro. The mechanical properties of PMMA were reduced from controls upon doxorubicin incorporation, likely stemming from doxorubicin inhibition of PMMA radical polymerization. SBB properties were not affected by doxorubicin incorporation and SBB eluted doxorubicin was fully efficacious in vitro compared to doxorubicin controls. These results indicate a likely inhibitory interaction between PMMA and doxorubicin, which affects both the strength of PMMA and the efficacy of doxorubicin. Further, this work illustrates SBB as a potential biomaterial alternative for traditional acrylics for medical biomaterial applications where load-bearing strength alongside drug delivery are key factors.

Virus-like particle (VLP) holds great promise for applications in vaccines and tumor immunotherapy. However, their clinical translation has been limited by a lack of comprehensive in vivo studies on immune responses and antigenic toxicity. In this study, we systematically evaluated the efficacy and safety of VLP as immunological agents. We administered Simian Virus 40 (SV40) VLP through subcutaneous injection and analyzed their effects on immune cell populations in key organs. In vivo imaging of mice demonstrated the migration of SV40 VLP between lymph nodes. Flow cytometry revealed that SV40 VLP significantly increased the numbers of CD4⁺ T cells and NK cells in the spleen, along with elevated levels of CD4⁺ T cells in mesenteric lymph nodes. Moreover, SV40 VLP did not significantly affect immune cell populations in the lungs, liver, or kidneys, nor did they alter blood biochemistry or coagulation parameters. Although SV40 VLP alone did not exhibit tumor-treating effects, in vitro imaging suggest that SV40 VLP can target tumor tissues and and quantitative analysis showed SV40 VLP significantly increased TNF-α expression in spleen. These findings suggest that SV40 VLP represent a promising tumor immunotherapy vector with potential for further modification.

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