Optimization, characterization and evaluation of ZnO/polyvinylidene fluoride nanocomposites for orthopedic applications: improved antibacterial ability and promoted osteoblast growth

Optimization, characterization and evaluation of sodium alginate nanoparticles for Ganoderic acid DM encapsulation: Inhibitory activity on tyrosinase activity and melanin formation

The efficacy of nanoencapsulation as a technology for enhancing the solubility of active substances has been demonstrated. In this particular investigation, Ganoderic acid DM (GA-DM) was encapsulated within sodium alginate nanoparticles (NPs) using the ionic crosslinking method. The confirmation of the successful loading of GA-DM was ascertained through the analysis of Fourier transform infrared spectrum (FTIR). Empirical evidence derived from the examination of scanning electron microscope (SEM) images, transmission electron microscope (TEM) images, atomic force microscope (AFM) images, and dynamic light scattering (DLS) demonstrated a regular distribution and spherical morphology, with an average particle size of approximately 133 nm. The investigation yielded an encapsulation efficiency of 95.27 ± 0.11 % and a drug loading efficiency of 21.17 ± 0.02 % for the prepared sample. The release kinetics of SGPN was fitted with the Korsmeyer-Peppas kinetic model corresponding to diffusion-controlled release. The incorporation of GA-DM into sodium alginate nanocarriers exhibited a mitigating effect on the cytotoxicity of HaCat and B16, while also demonstrating inhibitory properties against tyrosinase activity and melanin formation.

Scaffold-Based Poly(Vinylidene Fluoride) and Its Copolymers: Materials, Fabrication Methods, Applications, and Perspectives

Tissue engineering involves implanting grafts into damaged tissue sites to guide and stimulate the formation of new tissue, which is an important strategy in the field of tissue defect treatment. Scaffolds prepared in vitro meet this requirement and are able to provide a biochemical microenvironment for cell growth, adhesion, and tissue formation. Scaffolds made of piezoelectric materials can apply electrical stimulation to the tissue without an external power source, speeding up the tissue repair process. Among piezoelectric polymers, poly(vinylidene fluoride) (PVDF) and its copolymers have the largest piezoelectric coefficients and are widely used in biomedical fields, including implanted sensors, drug delivery, and tissue repair. This paper provides a comprehensive overview of PVDF and its copolymers and fillers for manufacturing scaffolds as well as the roles in improving piezoelectric output, bioactivity, and mechanical properties. Then, common fabrication methods are outlined such as 3D printing, electrospinning, solvent casting, and phase separation. In addition, the applications and mechanisms of scaffold-based PVDF in tissue engineering are introduced, such as bone, nerve, muscle, skin, and blood vessel. Finally, challenges, perspectives, and strategies of scaffold-based PVDF and its copolymers in the future are discussed.

Smart Orthopedic Biomaterials and Implants

Musculoskeletal injuries including bone defects continue to present a significant challenge in orthopedic surgery due to suboptimal healing. Bone reconstruction strategies focused on the use of biological grafts and bone graft substitutes in the form of biomaterials-based 3D structures in fracture repair. Recent advances in biomaterials science and engineering have resulted in the creation of intricate 3D bone-mimicking structures that are mechanically stable, biodegradable, and bioactive to support bone regeneration. Current efforts are focused on improving the biomaterial and implant physicochemical properties to promote interactions with the host tissue and osteogenesis. The "smart" biomaterials and their 3D structures are designed to actively interact with stem/progenitor cells and the extracellular matrix (ECM) to influence the local environment towards osteogenesis and de novo tissue formation. This article will summarize such smart biomaterials and the methodologies to apply either internal or external stimuli to control the tissue healing microenvironment. A particular emphasis is also made on the use of smart biomaterials and strategies to create functional bioactive implants for bone defect repair and regeneration.

Comparative review of piezoelectric biomaterials approach for bone tissue engineering

Bone as a minerals' reservoir and rigid tissue of the body generating red and white blood cells supports various organs. Although the self-regeneration property of bone, it cannot regenerate spontaneously in severe damages and still remains as a challenging issue. Tissue engineering offers several techniques for regenerating damaged bones, where various biomaterials are examined to fabricate scaffolds for bone repair. Piezoelectric characteristic plays a crucial role in repairing and regenerating damaged bone by mimicking the bone niche behavior. Piezoelectric biomaterials show significant potential for bone tissue engineering. Herein we try to have a comparative review on piezoelectric and non-piezoelectric biomaterials used in bone tissue engineering, classified them, and discussed their effects on implanted cells and manufacturing techniques. Especially, Polyvinylidene fluoride (PVDF) and its composites are the most practically used piezoelectric biomaterials for bone regeneration. PVDF and its composites have been summarized and discussed to repair damaged bone tissues.

A Bibliometric Analysis of Electrospun Nanofibers for Dentistry

Electrospun nanofibers have been widely used in dentistry due to their excellent properties, such as high surface area and high porosity, this bibliometric study aimed to review the application fields, research status, and development trends of electrospun nanofibers in different fields of dentistry in recent years. All of the data were obtained from the Web of Science from 2004 to 2021. Origin, Microsoft Excel, VOSviewer, and Carrot² were used to process, analyze, and evaluate the publication year, countries/region, affiliations, authors, citations, keywords, and journal data. After being refined by the year of publication, document types and research fields, a total of 378 publications were included in this study, and an increasing number of publications was evident. Through linear regression calculations, it is predicted that the number of published articles in 2022 will be 66. The most published journal about electrospun dental materials is Materials Science & Engineering C-Materials for Biological Applications, among the six core journals identified, the percent of journals with Journal Citation Reports (JCR) Q1 was 60%. A total of 17.60% of the publications originated from China, and the most productive institution was the University of Sheffield. Among all the 1949 authors, the most productive author was Marco C. Bottino. Most electrospun dental nanofibers are used in periodontal regeneration, and Polycaprolactone (PCL) is the most frequently used material in all studies. With the global upsurge in research on electrospun dental materials, bone regeneration, tissue regeneration, and cell differentiation and proliferation will still be the research hotspots of electrospun dental materials in recent years. Extensive collaboration and citations among authors, institutions and countries will also reach a new level.

A healing promoting wound dressing with tailor-made antibacterial potency employing piezocatalytic processes in multi-functional nanocomposites

Developing a novel antibiotics-free antibacterial strategy is essential for minimizing bacterial resistance. Materials that not only kill bacteria but also promote tissue healing are especially challenging to achieve. Inspired by chemical conversion processes in living organisms, we develop a piezoelectrically active antibacterial device that converts ambient O₂ and H₂O to ROS by piezocatalytic processes. The device is achieved by mounting nanoscopic polypyrrole/carbon nanotube catalyst multilayers onto piezoelectric-dielectric films. Under stimuli by a hand-held massage device, the sterilizing rates for S. aureus and E. coli reach 84.11% and 94.85% after 10 minutes of operation, respectively. The antibacterial substrate at the same time preserves and releases drugs and presents negligible cytotoxicity. Animal experiments demonstrate that daily treatment for 10 minutes using the device effectively accelerates the healing of infected wounds on the backs of mice, promoting hair follicle generation and collagen deposition. We believe that this report provides a novel design approach for antibacterial strategies in medical treatment.