Hybrid zinc oxide nanocoating on titanium implants: Controlled drug release for enhanced antibacterial and osteogenic performance in infectious conditions

Implantable Dental Barrier Membranes as Regenerative Medicine in Dentistry: A Comprehensive Review

BACKGROUND

Periodontitis and bone loss in the maxillofacial and dental areas pose considerable challenges for both functional and aesthetic outcomes. To date, implantable dental barrier membranes, designed to prevent epithelial migration into defects and create a favorable environment for targeted cells, have garnered significant interest from researchers. Consequently, a variety of materials and fabrication methods have been explored in extensive research on regenerative dental barrier membranes.

METHODS

This review focuses on dental barrier membranes, summarizing the various biomaterials used in membrane manufacturing, fabrication methods, and state-of-the-art applications for dental tissue regeneration. Based on a discussion of the pros and cons of current membrane strategies, future research directions for improved membrane designs are proposed.

RESULTS AND CONCLUSION

To endow dental membranes with various biological properties that accommodate different clinical situations, numerous biomaterials and manufacturing methods have been proposed. These approaches provide theoretical support and hold promise for advancements in dental tissue regeneration.

Synergistic effects of modified zinc oxide nanoparticle in a hybrid chitosan-gelatin hydrogel for bone regeneration

The development of composite hydrogels with enhanced biocompatibility and osteoconductivity remains a critical focus in bone tissue engineering. In this study, we designed a double-network hydrogel composed of chitosan, and gelatin (CG), crosslinked to improve its mechanical properties for bone regeneration applications. To further enhance its bioactivity, zinc oxide nanoparticles (ZnO) were incorporated into the hydrogel matrix. Prior to incorporation, ZnO was functionalized with a mussel-inspired polydopamine (PDA) coating, forming ZnO/PDA. Subsequently, in situ mineralization facilitated the deposition of calcium and phosphate (CaP) ions, yielding ZnO/PDA/CaP (m-ZnO). To evaluate the effects of these modifications, three hydrogel formulations were prepared: pure CG hydrogel, CG hydrogel containing ZnO/PDA (CG@Z/P), and CG hydrogel incorporated with m-ZnO (CG@m-ZnO). The addition of m-ZnO significantly enhanced the compressive strength of CG@m-ZnO, increasing it from 335.05 ± 8.35 kPa to 973.31 ± 102.19 kPa, while maintaining microstructural integrity. The incorporation of ZnO also imparted antibacterial properties, whereas the PDA and CaP layers promoted cell adhesion and proliferation. Notably, CG@m-ZnO with 50 μg/mL of m-ZnO exhibited excellent biocompatibility and significantly enhanced osteogenic differentiation of MC3T3-E1 cells, as evidenced by increased alkaline phosphate (ALP) activity and Alizarin Red S (ARS) staining. In conclusion, the CG@m-ZnO hydrogel demonstrates a synergistic combination of biocompatibility, osteoconductivity, antibacterial activity, and enhanced mechanical properties, making it a promising candidate for bone tissue engineering and regenerative medicine applications.

3D printed Gel/PTH@PAHA scaffolds with both enhanced osteogenesis and mechanical properties for repair of large bone defects

The repair of large bone defects continues to pose a significant challenge in clinical orthopedics. Successful repairs require not only adequate mechanical strength but also exceptional osteogenic activity for successful clinical translation. Composite materials based on polyamide 66 (PA66) and hydroxyapatite have been widely used in various clinical settings. However, existing PA66/hydroxyapatite composites often lack sufficient osteogenic stimulation despite their favorable mechanical properties, which limit their overall clinical efficacy. In this study, we fabricated a polyamide 66/nano-hydroxyapatite (PAHA) scaffold using an extruder and fused deposition modeling-based 3D printing technology. Subsequently, gelatin methacrylamide (GelMA) containing teriparatide (PTH) was incorporated into the PAHA scaffold to construct the Gel/PTH@PAHA scaffold. Material characterization results indicated that the compressive modulus of elasticity and compressive strength of the Gel/PTH@PAHA scaffold were 172.47 ± 5.48 MPa and 25.55 ± 2.19 MPa, respectively. In vitro evaluations demonstrated that the Gel/PTH@PAHA scaffold significantly enhanced osteoblast adhesion and proliferation while promoting osteogenic differentiation of BMSCs. In vivo studies further revealed that this scaffold notably promoted new bone regeneration in rabbit femoral defects. These findings suggest that the 3D-printed Gel/PTH@PAHA scaffold exhibits excellent mechanical properties alongside remarkable osteogenic activity, thereby meeting the dual requirements for load-bearing applications and bone regeneration. This innovative approach may be a promising candidate for customized orthopedic implants with substantial potential for clinical application.

Chitosan-encapsulated bacteriophage cocktail as promising oral delivery system to surpass gastrointestinal infection caused by Klebsiella aerogenes

Bacteriophages hold promise for combating pathogenic bacteria in the human intestinal tract, but their therapeutic potential is limited by harsh stomach conditions, including low pH and digestive enzymes. This study aimed to develop a natural protective mechanism for orally administering phages to treat gastric infections caused by Klebsiella aerogenes. Results revealed that free phages became inactive at pH 3 without protective measures. Encapsulation within sodium alginate (SA) alone (Bead 1) enabled phage survival at pH 2.5. More notably, Bead 2, consisting of a phage cocktail encapsulated in a chitosan-SA matrix supplemented with honey, casein, and gelatin, demonstrated enhanced survival even at pH 1.5. Phage titers in Bead 2 exhibited a controlled release, with near-complete discharge over 5 h in a simulated intestinal solution at 37 °C, ensuring effective delivery to the intestinal environment. Exposure of K. aerogenes to Bead 2 under these conditions resulted in a maximum reduction of 6.2 log10 CFU/mL, compared to maximal reductions of 2.8 log10 CFU/mL for Bead 1 and free phages. This optimized bead-encapsulation method provides a viable, efficient, and cost-effective strategy for delivering functional phages to specifically target intestinal bacteria.