Comparison of skeletal muscle decellularization protocols and recellularization with adipose-derived stem cells for tissue engineering.

Decellularization is a novel technique employed for scaffold manufacturing, as a strategy for skeletal muscle (SM) tissue engineering applications. However, poor decellularization efficacy is still a problem for the use of decellularized scaffolds as truly biocompatible biomaterials. For recellularization, adipose-derived stem cells (ASCs) are a good option, due to their immunomodulatory and pro-regenerative capacity, but few studies have described their combination with muscle-decellularized matrices (mDMs). This work aimed to evaluate the efficiency of four multi-step decellularization protocols to produce mDMs and to investigate in vitro biocompatibility with ASCs. Here, we described the different efficacies of muscle decellularization methods, suggesting the need for stricter standardization of the method, considering the large range of applications in SM tissue engineering, which is also a promising platform for preclinical studies with rat disease models using autologous cells.

Nanosilver-Functionalized Hybrid Hydrogels of Carboxymethyl Cellulose/Poly(Vinyl Alcohol) with Antibacterial Activity for Prevention and Therapy of Infections of Diabetic Chronic Wounds.

Diabetic foot ulcers (DFUs) are considered one of the most severe chronic complications of diabetes and can lead to amputation in severe cases. In addition, bacterial infections in diabetic chronic wounds aggravate this scenario by threatening human health. Wound dressings made of polymer matrices with embedded metal nanoparticles can inhibit microorganism growth and promote wound healing, although the current clinical treatments for diabetic chronic wounds remain unsatisfactory. In this view, this research reports the synthesis and characterization of innovative hybrid hydrogels made of carboxymethyl cellulose (CMC) and poly(vinyl alcohol) (PVA) chemically crosslinked by citric acid (CA) functionalized with silver nanoparticles (AgNPs) generated in situ using an eco-friendly aqueous process. The results assessed through comprehensive in vitro and in vivo assays demonstrated that these hybrid polymer hydrogels functionalized with AgNPs possess physicochemical properties, cytocompatibility, hemocompatibility, bioadhesion, antibacterial activity, and biocompatibility suitable for wound dressings to support chronic wound healing process as well as preventing and treating bacterial infections. Hence, it can be envisioned that, with further research and development, these polymer-based hybrid nanoplatforms hold great potential as an important tool for creating a new generation of smart dressings for treating chronic diabetic wounds and opportunistic bacterial infections.

Avaliação topográfica e in vitro de superfícies de titânio revestidas com vidro bioativo / Topographic and in vitro evaluation of titanium surfaces coated with bioative glass

Objetivo: Avaliar e comparar a rugosidade superficial e a atividade dos osteoblastos em contato com uma nova superfície bioativa e nanoestruturada de titânio grau 4 revestida com vidro bioativo contendo fosfato de cálcio, sintetizada pelo método sol-gel. Material e método: Sessenta e três discos de titânio, medindo 4 mm de diâmetro por 2 mm de altura, foram preparados e divididos em três grupos: microtexturizado (Ticp - controle); revestido com vidro bioativo e seco a vácuo a 37 °C por 10 dias (BGTi37), e revestido com vidro bioativo e aquecido a 600 °C por cinco horas (BGTi600). Três espécimes de cada grupo foram utilizados para avaliação da topografia superficial e 18 espécimes, para cultura celular. Resultado: O revestimento de vidro bioativo diminuiu a rugosidade média quando comparado ao titânio microtexturizado. A proporção de células viáveis, a produção de fosfatase alcalina e o grau de mineralização da matriz óssea em contato com os espécimes de titânio do grupo BGTi600 foram significativamente menores em relação aos grupos controle e do titânio microtexturizado. Conclusão: Apesar de sua marcante menor rugosidade, a superfície BGTi37 apresentou comportamento biológico semelhante a uma superfície de titânio microtexturizada e moderadamente rugosa. A outra superfície experimental (BGTi600), a de menor rugosidade entre todas as testadas, apresentou os piores resultados de ativação dos osteoblastos.

Objective: To evaluate and compare the surface roughness and the activity of the osteoblasts in contact with a new bioactive and nanostructured surface of grade 4 titanium coated with bioactive glass containing calcium phosphate synthesized by the sol-gel method. Material and method: Sixty-three titanium disks, measuring 4 × 2 mm, were prepared and divided into three groups: rough surface, obtained by sandblasted, large-grit, acid-etched (SLA) treatment (Ticp); SLA surface coated with bioglass and dried in a vacuum at 37 °C for 10 days (BGTi37) and SLA surface coated with bioglass and dried in air at 600 °C for 5 hours (BGTi600). Three specimens of each group were used for evaluation of surface topography and 18 for cell cultures. Result: The bioactive glass coating decreased the average roughness when compared to rough titanium surface. The proportion of viable cells, the production of alkaline phosphatase and the degree of mineralization of the bone matrix in contact with the titanium specimens of the BGTi600 group was significantly lower in relation to the control and rough titanium surface groups. Conclusion: Despite its marked lower roughness, BGTi37 surface presented a similar biological behavior to a titanium rough surface obtained by SLA treatment. The other experimental surface (BGTi600), the one with the least roughness among all tested, presented the worst results of osteoblast activation.

Narrow-implant-retained overdenture in an atrophic mandibular ridge: a case report with 6-year follow-up.

When atrophic jaws compromise oral rehabilitation with conventional implants, narrow-diameter implants can be used. This case report describes treatment of an edentulous 75-year-old diabetic woman with a severely resorbed mandibular ridge. Her mandibular dentition was restored with an overdenture supported by 3 narrow implants and 1 mini implant. Her maxillary dentition was restored with a conventional complete denture. A 6-year clinical and radiographic follow-up confirmed that the narrow implants had provided effective stability for the overdenture, providing improvements in phonetics and masticatory ability at a low cost.