With the increase in the population’s life expectancy, there has also been an increase in the rate of osteoporosis, which has expanded the search for strategies to regenerate bone tissue. The ultrasonic sonochemical technique was chosen for the functionalization of the 45S5 bioglass. The samples after the sonochemical process were divided into (a) functionalized bioglass (BG) and (b) functionalized bioglass with 10% teriparatide (BGT). Isolated mesenchymal cells (hMSC) from femurs of ovariectomized rats were differentiated into osteoblasts and submitted to in vitro tests. Bilateral ovariectomy (OVX) and sham ovariectomy (Sham) surgeries were performed in fifty-five female Wistar rats. After a period of 60 days, critical bone defects of 5.0 mm were created in the calvaria of these animals. For biomechanical evaluation, critical bone defects of 3.0 mm were performed in the tibias of some of these rats. The groups were divided into the clot (control) group, the BG group, and the BGT group. After the sonochemical process, the samples showed modified chemical topographic and morphological characteristics, indicating that the surface was chemically altered by the functionalization of the particles. The cell environment was conducive to cell adhesion and differentiation, and the BG and BGT groups did not show cytotoxicity. In addition, the experimental groups exhibited characteristics of new bone formation with the presence of bone tissue in both periods, with the BGT group and the OVX group statistically differing from the other groups (p < 0.05) in both periods. Local treatment with the drug teriparatide in ovariectomized animals promoted positive effects on bone tissue, and longitudinal studies should be carried out to provide additional information on the biological performance of the mutual action between the bioglass and the release of the drug teriparatide.

Background: The 3D printing of macro- and mesoporous biomimetic grafts composed of polycaprolactone (PCL) infused with nanosized synthetic smectic clay is a promising innovation in biomaterials for bone tissue engineering (BTE). The main challenge lies in achieving a uniform distribution of nanoceramics across low to high concentrations within the polymer matrix while preserving mechanical properties and biological performance essential for successful osseointegration. Methods: This study utilized 3D printing to fabricate PCL scaffolds enriched with nanosized synthetic smectic clay (LAP) to evaluate its effects on structural, chemical, thermal, mechanical, and degradative properties, with a focus on in vitro biological performance and non-toxicity. Scaffolds were created with varying proportions of PCL and LAP. Comprehensive characterization included scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), mechanical testing, swelling analysis, and degradation studies. Biological performance was assessed through MTT assays (cell viability), alkaline phosphatase activity, histological analysis, and Raman spectroscopy, highlighting the scaffolds’ biocompatibility and potential applications in regenerative medicine. Results: The developed inks demonstrated excellent injectability, and the 3D-printed PCL/LAP scaffolds exhibited a microporous and rough structure, good structural fidelity, low degradability, thermal stability, and sufficient mechanical strength across all formulations. Intrinsic properties of the scaffolds revealed no cytotoxicity while enhancing bioactivity and promoting in vitro mineralization when cultured with mesenchymal stem cells in all analyzed groups. Notably, the high concentration of LAP within the PCL matrices did not induce in vitro cytotoxicity but rather stimulated in vitro mineralization and differentiation. Conclusion: This study demonstrated the feasibility of 3D printing PCL/LAP scaffolds with high concentrations of nanoceramics. Both in vitro and in vivo assays validated the regenerative potential of these scaffolds, emphasizing their efficacy as a promising approach for developing advanced biomimetic grafts.

Background: Radiotherapy can affect healthy cells, resulting in side effects. This study aimed to assess the impact of radiotherapy on soft tissue in surgical wounds in rats. Methods: The animals were divided into four groups: control (S) group without irradiation, immediate irradiation (S-IIr) group receiving irradiation right after surgery, late irradiation (S-LIr) group receiving irradiation four weeks after surgery, and early irradiation (Ir-S) group receiving irradiation before surgery. The irradiated groups underwent two fractional stages of 15 Gy. Muscle contractibility (EMG) was evaluated at two different time points, and after 2 and 7 weeks, the animals were euthanized for histological analysis of the muscles and skin. Results: There was no significant difference between the EMG1 and EMG2 values of the S and S-LIr groups, but both S-IIr and Ir-S groups exhibited a statistically significant difference. The S group demonstrated a larger diameter of muscle fiber compared to other groups, showing a significant difference. In terms of skin analysis, the S-IIr group had the least inflammatory infiltrate and the highest amount of red fibers, differing significantly from the other groups. Conclusions: Regardless of the duration, radiotherapy was found to have effects on the surrounding soft tissues, as concluded by this study.

Purpose: The objective of this study was to evaluate the effects of Gamma irradiation by simulating a total dose of conventional head and neck cancer radiotherapy on bone remodeling and osseointegration of implants in femurs of rats.Materials and Methods: Sixty rats received threaded titanium (Ti6Al4V) implants in both femurs. The animals were divided: No-Irradiation (N-Ir): N-Ir group with implant solely, Early-Irradiation (E-Ir): implant + irradiation after 24hrs.; Late-Irradiation (L-Ir): implant + irradiation after 4 weeks and Previous-Irradiation (P-Ir): irradiation + implant after 4 weeks. Irradiation was fractioned in two sessions of 15 Gy each, totaling 30 Gy. The animals were euthanized at 3 days, 2 and 7 weeks after treatment, which were chosen from previous studies. Runx2 immunohistochemical markers and Picrosirius red stain, histomorphometric analysis (BIC and BAFO) and reverse torque test were used to evaluate the implant/bone interface and surrounding bone. Data of Runx-2 (%), picrosirius red stain (%), BIC and BAFO (%), and reverse torque (N/cm) was submitted to ANOVA and Tukey tests for comparison among groups, both with α=0.05. Results: The results showed that Runx-2 expression was different in irradiated groups when compared to N-Ir group. In general, the collagen fiber analyses in the irradiated groups differed from the N-Ir group. Regarding BIC, BAFO, and the reverse torque test, the L-Ir group demonstrated results similar to the N-Ir group, while the others groups were impaired by radiotherapy. Conclusions: Ionizing radiation negatively affected bone remodeling, and its effect depends on when radiotherapy is applied, with a delay of osseointegration when applied previously or close to surgery.