Lidocaine HCl-Loaded Polyelectrolyte Complex -Poloxamer Thermoresponsive Hydrogel: In Vitro- In Vivo Anesthetic Evaluations for Tooth Socket Wound Delivery.

Local anesthesia is essential in dental practices, particularly for managing pain in tooth socket wounds, yet improving drug delivery systems remains a significant challenge. This study explored the physicochemical characteristics of lidocaine hydrochloride (LH) incorporated into a polyelectrolyte complex and poloxamer thermosensitivity hydrogel, assessing its local anesthetic efficacy in mouse models and its onset and duration of action as topical anesthetics in clinical trials. The thermoresponsive hydrogel exhibited a rapid phase transition within 1-3 minutes and demonstrated pseudo-plastic flow behavior. Its release kinetics followed Korsmeyer-Peppas, with 50% of biodegradation occurring over 48 h. In mouse models, certain thermogels showed superior anesthetic effects, with rapid onset and prolonged action, as evidenced by heat tolerance in tail-flick and hot plate models. In clinical trials, the LH-loaded thermoresponsive hydrogel provided rapid numbness onset, with anesthesia (Ton) beginning at an average of 46.5 ± 22.5 seconds and lasting effectively (Teff) for 202.5 ± 41.0 seconds, ranging from 120 to 240 seconds, indicating sustained release. These results highlight the promising properties of these formulations: rapid onset, prolonged duration, mucoadhesion, biodegradability, and high anesthesia effectiveness. This study demonstrates the potential for advancing local anesthesia across various medical fields, emphasizing the synergy between material science and clinical applications to improve patient care and safety.

Formulation development and evaluation of lidocaine hydrochloride loaded in chitosan-pectin-hyaluronic acid polyelectrolyte complex for dry socket treatment.

The main purpose of this study was to assess a lidocaine hydrochloride-loaded chitosan-pectin-hyaluronic polyelectrolyte complex for rapid onset and sustained release in dry socket wound treatment. Nine formulations (LCs) of lidocaine hydrochloride (LH) loaded into a chitosan-pectin-hyaluronic polyelectrolyte complex (PEC) were assessed using full factorial design (two factors × three levels). The formulations ranged between 4 and 10% w/w LH and 0.5-1.5% w/w HA. The following physicochemical properties of LCs were characterized: size, zeta potential, % entrapment efficiency, viscosity, mucoadhesiveness, % drug release, morphology, storage stability, and cytotoxicity. The particle size, zeta potential, % EE, viscosity, and % mucoadhesion increased with increasing LH and HA concentrations. Rapid release of LH followed a zero-order model, and a steady-state percentage of the drug was released over 4 h. LCs were found to be non-cytotoxic compared to LH solution. LH loaded into PEC demonstrated appropriate characteristics-including suitable rate of release-and fit a zero-order model. Furthermore, it was not cytotoxic and showed good stability in a high-HA formula, making it a promising candidate for future topical oral formulations.

Treatment of Peri-Implant Defects in the Rabbit's Tibia with Adipose or Bone Marrow-Derived Mesenchymal Stems Cells.

BACKGROUND: Mesenchymal stem cell (MSC) treatment in conjunction with bone graft materials or space filler can be an alternative to autogenous bone grafts in the treatment of peri-implant bone defects. PURPOSE: To evaluate the success of bone regeneration capacity of adipose-derived and bone marrow-derived MSCs for the treatment of peri-implant bone defects when applied with a beta-tricalcium phosphate/collagen-based scaffold. MATERIAL AND METHODS: Forty implants were placed into the tibiae of 10 rabbits bilaterally. Surgical defects created around the implants were treated with one the following treatment modalities: 1) adipose-derived MSC transplanted scaffold + collagen membrane; 2) bone marrow-derived MSC transplanted scaffold + collagen membrane; 3) autogenous bone + collagen membrane; and 4) collagen membrane only. The bone regeneration capacity of each technique was determined by histomorphometry, micro-CT, and measuring the implant stability by resonance frequency analysis. RESULTS: One limb of one rabbit was excluded because of fracture, and another limb was excluded because of infection. All parameters on 36 implants revealed that both sources of MSC can form equivalently new bone that is comparable with autogenous bone. The defects treated with membrane only had significantly less bone formation compared with other groups. CONCLUSION: Both adipose-derived and bone marrow-derived MSC treatments are feasible alternatives to autogenous bone grafts in the treatment of peri-implant osseos defects.