Biocomposite-based strategies for dental bone regeneration

Guided bone regeneration using beta-tricalcium phosphate and leucocyte platelet-rich fibrin versus a novel biodegradable urethane composite in critical-size osseous defects in rabbit tibia: Histologic results of a pilot study

BACKGROUND

Insufficient bone volume is a major problem in implant dentistry, which can be counteracted by using guided bone regeneration technique. Among the materials recently tested, synthetic polymers have been recommended as showing excellent biocompatibility and biodegradability.

OBJECTIVE

The aim of this pilot study was to analyze and compare through means of histology the healing of the bone tissue in critical size osseous defects in New-Zealand rabbit tibiae after application of beta-tricalcium phosphate (β-TCP) alone, β-TCP combined with leucocyte platelet-rich fibrin (L-PRF) and an injectable experimental bone cement (EBC) represented by a dual-curable degradable synthetic polymer.

METHODS

Two New-Zealand rabbits were used. Three standardized osseous defects of 5 mm diameter were created in each tibia. Each defect was filled with either β-TCP alone (control), β-TCP combined with L-PRF (test) or with EBC (test). The animals were sacrificed at 25 and 70 days; the tibia samples were removed, fixed in 10 % formaldehyde and stained with AZAN.

RESULTS

While at 25 days β-TCP produced sparse bone formation, at 70 days mature bone formation was visible in all areas of the defect with minimum remaining graft particles; at 25 days, β-TCP combined with L-PRF produced broad areas of bone lamellae, while at 70 days bone tissue formation was limited; at both 25 and 70 days, the EBC was stable and not penetrated by bone cells, while a narrow band of connective tissue could be seen superjacent and inferior to it.

CONCLUSIONS

Among the tested biomaterials, β-TCP was capable of generating bone formation at both healing time-points, while the addition of L-PRF seemed to provide a synergistic effect only in the early phase of bone healing.

Clinical evaluation of full mouth disinfection and azithromycin in chronic periodontitis: randomized clinical trial

This randomized, double-blind clinical trial assessed the clinical and microbiological effects of systemic azithromycin (AZ) as an adjunct to one-stage full-mouth disinfection (OSFMD) in patients with moderate to severe chronic periodontitis. Forty-two patients were assigned to OSFMD with either AZ or placebo. Clinical parameters and bacterial counts were evaluated at baseline, 90, and 180 days. Both groups showed significant reductions in probing pocket depth (PPD), attachment loss, bleeding, and plaque scores over time; however, no statistically significant intergroup differences were observed in clinical outcomes (p > 0.05). In contrast, the AZ group showed a statistically significant reduction in total bacterial counts and specific periodontopathogens (p < 0.05). Oral health-related quality of life (OHQOL) improved significantly in both groups 2 weeks post-treatment. Although AZ provided enhanced microbiological benefits, its adjunctive use did not yield additional clinical improvements. These findings suggest that routine use of AZ may not be justified for all patients undergoing OSFMD, though benefits may exist for selected high-risk cases.

Factors associated with tooth loss in patients with stages 3 and 4 periodontitis: a short-term retrospective evaluation of patients

This retrospective study analyzed factors associated with tooth loss in patients with stages 3 and 4 periodontitis undergoing non-surgical periodontal therapy. Data from 84 patients treated at Griffith University Periodontal Clinic (2019-2022) were examined, focusing on patient factors such as smoking status, osteoporosis, and age, alongside tooth loss variables. The logistic regression analysis revealed that patients with stage 4 periodontitis had a significantly higher likelihood of tooth loss compared to those with stage 3 (odds ratio [OR] 2.12; 95% confidence interval [CI] 1.13-4.84). Smoking was also identified as a significant risk factor, with smokers showing an OR of 1.69 (95% CI 1.4-3.9) for tooth loss. While no statistically significant relationships were observed for other variables (p > 0.05), patients under 40 years and over 71 years with stage 4 periodontitis exhibited notable tooth loss outcomes (p = 0.003 and p = 0.034, respectively). These findings emphasize the importance of integrating smoking cessation programs into periodontal care and tailoring treatment strategies for high-risk groups. Further longitudinal studies with comprehensive data collection are recommended to enhance the understanding of tooth loss predictors in advanced periodontitis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-025-04217-5.

Microsponges: Development, Characterization, and Key Physicochemical Properties

Microsponges are promising drug delivery carriers with versatile characteristics and controlled release properties for the delivery of a wide range of drugs. The microsponges will provide an optimized therapeutic effect, when delivered at the site of action without rupturing, then releasing the cargo at the predetermined time and area. The ability of the microsponges to effectively deliver the drug in a controlled manner depends on the material composition. This comprehensive review entails knowledge on the design parameters of an optimized microsponge drug delivery system and the controlled release properties of microsponges that reduces the side effects of drugs. Furthermore, the review delves into the fabrication techniques of microsponges, the mechanism of drug release from the microsponges, and the regulatory requirements of the U.S. Food and Drug Administration (FDA) for the successful marketing of microsponge formulation. The review also examines the patented formulations of microsponges. The prospects of these sophisticated drug delivery systems for improved clinical outcomes are highlighted.

Developing Engineered Nano-Immunopotentiators for the Stimulation of Dendritic Cells and Inhibition and Prevention of Melanoma

OBJECTIVE

This study aims to utilize PEGylated poly (lactic-co-glycolic acid) (PLGA) nanoparticles as a delivery system for simultaneous administration of the BRAFV600E peptide, a tumor-specific antigen, and imiquimod (IMQ). The objective is to stimulate dendritic cell (DC) maturation, activate macrophages, and facilitate antigen presentation in C57BL6 mice.

METHODS

PEG-PLGA-IMQ-BRAFV600E nanoparticles were synthesized using a PLGA-PEG-PLGA tri-block copolymer, BRAFV600E, and IMQ. Characterization included size measurement and drug release profiling. Efficacy was assessed in inhibiting BPD6 melanoma cell growth and activating immature bone marrow DCs, T cells, macrophages, and splenocyte cells through MTT and ELISA assays. In vivo, therapeutic and immunogenic effects potential was evaluated, comparing it to IMQ + BRAFV600E and PLGA-IMQ-BRAFV600E nanoparticles in inhibiting subcutaneous BPD6 tumor growth.

RESULTS

The results highlight the successful synthesis of PEG-PLGA-IMQ-BRAFV600E nanoparticles (203 ± 11.1 nm), releasing 73.4% and 63.2% of IMQ and BARFV600E, respectively, within the initial 48 h. In vitro, these nanoparticles demonstrated a 1.3-fold increase in potency against BPD6 cells, achieving ~ 2.8-fold enhanced cytotoxicity compared to PLGA-IMQ-BRAFV600E. Moreover, PEG-PLGA-IMQ-BRAFV600E exhibited a 1.3-fold increase in potency for enhancing IMQ cytotoxic effects and a 1.1- to ~ 2.4-fold increase in activating DCs, T cells, macrophages, and splenocyte cells compared to IMQ-BRAFV600E and PLGA-IMQ-BRAFV600E. In vivo, PEG-PLGA-IMQ-BRAFV600E displayed a 1.3- to 7.5-fold increase in potency for inhibiting subcutaneous BPD6 tumor growth compared to the other formulations.

CONCLUSIONS

The findings suggest that PEG-PLGA nanoparticles effectively promote DC maturation, T cell activation, and potentially macrophage activation. The study highlights the promising role of this nanocomposite in vaccine development.

Resorbable GBR Scaffolds in Oral and Maxillofacial Tissue Engineering: Design, Fabrication, and Applications

Guided bone regeneration (GBR) is a promising technique in bone tissue engineering that aims to replace lost or injured bone using resorbable scaffolds. The promotion of osteoblast adhesion, migration, and proliferation is greatly aided by GBR materials, and surface changes are critical in imitating the natural bone structure to improve cellular responses. Moreover, the interactions between bioresponsive scaffolds, growth factors (GFs), immune cells, and stromal progenitor cells are essential in promoting bone regeneration. This literature review comprehensively discusses various aspects of resorbable scaffolds in bone tissue engineering, encompassing scaffold design, materials, fabrication techniques, and advanced manufacturing methods, including three-dimensional printing. In addition, this review explores surface modifications to replicate native bone structures and their impact on cellular responses. Moreover, the mechanisms of bone regeneration are described, providing information on how immune cells, GFs, and bioresponsive scaffolds orchestrate tissue healing. Practical applications in clinical settings are presented to underscore the importance of these principles in promoting tissue integration, healing, and regeneration. Furthermore, this literature review delves into emerging areas of metamaterials and artificial intelligence applications in tissue engineering and regenerative medicine. These interdisciplinary approaches hold immense promise for furthering bone tissue engineering and improving therapeutic outcomes, leading to enhanced patient well-being. The potential of combining material science, advanced manufacturing, and cellular biology is showcased as a pathway to advance bone tissue engineering, addressing a variety of clinical needs and challenges. By providing this comprehensive narrative, a detailed, up-to-date account of resorbable scaffolds' role in bone tissue engineering and their transformative potential is offered.