Injectable ChitHCl-DDA tissue adhesive with high adhesive strength and biocompatibility for torn meniscus repair and regeneration.

Suture pull-through is a clinical problem in meniscus repair surgery due to the sharp leading edge of sutures. Several tissue adhesives have been developed as an alternative to traditional suturing; however, there is still no suitable tissue adhesive specific for meniscus repair treatment due to unsatisfactory biosafety, biodegradable, sterilizable, and tissue-bonding characteristics. In this study, we used a tissue adhesive composed of chitosan hydrochloride reacted with oxidative periodate-oxidized dextran (ChitHCl-DDA) combined with a chitosan-based hydrogel and oxidative dextran to attach to the meniscus. We conducted viscoelastic tests, viscosity tests, lap shear stress tests, Fourier transform infrared (FTIR) spectroscopy, swelling ratio tests, and degradation behavior tests to characterize these materials. An MTT assay, alcian blue staining, migration assay, cell behavior observations, and protein expression tests were used to understand cell viability and responses. Moreover, ex vivo and in vivo tests were used to analyze tissue regeneration and biocompatibility of the ChitHCl-DDA tissue adhesive. Our results revealed that the ChitHCl-DDA tissue adhesive provided excellent tissue adhesive strength, cell viability, and cell responses. This tissue adhesive has great potential for torn meniscus tissue repair and regeneration.

Intramedullary Nail vs. Plate Fixation for Pathological Humeral Shaft Fracture: An Updated Narrative Review and Meta-Analysis of Surgery-Related Factors.

(1) Background: Pathological humeral shaft fracture (PHSF) is a frequently observed clinical manifestation in the later stages of tumor metastasis. Surgical interventions are typically recommended to alleviate pain and restore functionality. Intramedullary nail fixation (INF) or plate fixation (PF) is currently recommended for the treatment of PHSF. However, there is still no standard for optimal surgical treatment. Thus, we conducted a meta-analysis comparing the clinical outcomes of INF with PF for PHSF treatment. (2) Methods: We conducted searches in databases, such as Scopus, EMBASE, and PubMed, for studies published prior to May 2023. In total, nine studies with 485 patients were reviewed. (3) Results: There were no significant differences noted in the incidence of fixation failure, local recurrence, wound complication or overall complication. However, the INF group demonstrated a significantly lower incidence of postoperative radial nerve palsy than the PF group (OR, 5.246; 95% CI, 1.548-17.774; p = 0.008). A subgroup analysis indicated that there were no statistically significant differences in fixation failure or local recurrence among subgroups categorized by the design of intramedullary nail. (4) Conclusions: Considering the short life expectancy of end-stage patients, the choice of surgical method depends on the patient's individual condition, fracture and lesion patterns, the surgeon's experience, and comprehensive discussion between the surgeon and patient.

Development and evaluation of an injectable ChitHCl-MgSO4-DDA hydrogel for bone regeneration: In vitro and in vivo studies on cell migration and osteogenesis enhancement.

Nonunion and delayed union of the bone are situations in orthopedic surgery that can occur even if the bone alignment is correct and there is sufficient mechanical stability. Surgeons usually apply artificial bone grafts in bone fracture gaps or in bone defect sites for osteogenesis to improve bone healing; however, these bone graft materials have no osteoinductive or osteogenic properties, and fit the morphology of the fracture gap with difficulty. In this study, we developed an injectable chitosan-based hydrogel with MgSO4 and dextran oxidative, with the purpose to improve bone healing through introducing an engineered chitosan-based hydrogel. The developed hydrogel can gelate and fit with any morphology or shape, has good biocompatibility, can enhance the cell-migration capacity, and can improve extracellular calcium deposition. Moreover, the amount of new bone formed by injecting the hydrogel in the bone tunnel was assessed by an in vivo test. We believe this injectable chitosan-based hydrogel has great potential for application in the orthopedic field to improve fracture gap healing.