The main mechanisms by which nanoparticles influence the bone microniche to direct osteogenesis. Nanoparticles modulate immune responses, induce osteogenic and angiogenic differentiation while suppressing osteoclast activity and differentiation.

Herein, the authors synthesised chitosan nanoparticles (Cs NPs) as a resveratrol (RSV) carrier and evaluated their efficacy in stimulating apoptosis in MDA‐MB 231 cells. Blank (Cs NPs) and RSV‐ Cs NPs (RSV‐Cs NPs) were synthesised via ionic gelation and characterised by using fourier‐transform infrared spectroscopy (FTIR), Scanning electron microscope, dynamic light scattering/Zeta potential and RSV release. MDA‐MB 231 cells were treated with RSV, Cs NPs and RSV‐Cs NPs (24, 48, and 72 h), followed by the 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide assay. Cell toxicity was evaluated using lactate dehydrogenase assay, and real‐time polymerase chain reaction was performed to explore apoptosis induction. FTIR spectra confirmed the NPs via the formation of cross‐linking bonds. Cs and RSV‐Cs NPs sizes were about 75 and 198 nm with 14 and 24 mV zeta potentials. The RSV entrapment efficiency was 52.34 ± 0.16%, with an early rapid release followed by a sustained manner. Cs and RSV‐Cs NPs inhibited cell proliferation at lower concentrations and IC50 values. RSV‐Cs NPs had the most cytotoxic effect and stimulated intrinsic apoptotic pathway, indicated by increased Bcl‐2‐associated x (BAX), BAX/Bcl‐2 ratio, P53 expressions, reduced Bcl‐2 and upregulated caspases 3, 8 and 9. RSV‐Cs NPs have a great potential to suppress invasive breast cancer cell proliferation by targeting mitochondrial metabolism and inducing the intrinsic apoptotic pathway.

Osteosarcoma is a common bone malignancy in patients of all ages. Surgical and chemotherapy interventions fail to shrink tumor growth and metastasis. The development of efficient patient-specific therapeutic strategies for osteosarcoma is of great interest in tissue engineering and personalized medicine. The present manuscript aimed to review the advancements in tissue engineering and personalized medicine strategies to overcome osteosarcoma and the relevant biological aspects as well as the current tumor models in vitro and in vivo. Tissue engineering and personalized medicine contribute to gene/cell engineering and cell-based therapies specific to genomic and proteomic profiles of individual patients to improve the current treatment options. Also, tissue engineering scaffolds provide physical support to missing bones, could trap cancer cells and deliver immune cells. Taken together, these strategies suppress tumor growth, angiogenic potential, and the subsequent metastasis as well as elicit desirable immune responses against tumor mass. Advanced and high-throughput gene and protein identification technologies have facilitated the recognition of genomic and proteomic profiles of patients to design and develop patient-specific treatments. The pre-clinical studies showed promising outcomes to inhibit tumor growth and invasion but controversial results compared to clinical investigations make the importance of more clinical reports inevitable. The experimental tumor models assist the evolution of effective treatments by understanding the mechanisms of tumor progression. Tissue engineering and personalized medicine strategies seem encouraging alternatives to conventional therapies against osteosarcoma. Modeling the tumor microenvironment coupled with pre-clinical results give new intelligence into the translation of strategies into the clinic.

Introduction: Fabricating composite scaffolds with improved physicochemical properties as artificial microenvironments are of great interest in bone tissue engineering. Given advantageous properties of nano-hydroxyapatite/chitosan/gelatin (nHA/Cs/Gel) scaffolds, the present study aimed to synthesize a modified nHA/Cs/Gel biomimetic scaffold with improved features. Methods: Pure and copper (Cu)-substituted nHA was synthesized using the chemical precipitation method under controlled pH and temperature. Pure and Cu-substituted nHA/Cs/Gel scaffolds were fabricated by salt-leaching/freeze-drying method. Physicochemical characteristics of nanoparticles and scaffolds were explored using XRD, FTIR, FE-SEM/EDX, and ICP. Besides, scaffold mechanical strength, degradation, porosity, swelling, biomineralization, and cytocompatibility were assessed. Results: Pure and Cu-substituted nHA were synthesized and characterized with appropriate Cu substitution and improved physical properties. All scaffolds were highly porous (porosity >98%) and Cu incorporation reduced porosity from 99.555 ± 0.394% to 98.69 ± 0.80% while enlarged the pore size to more than100 µm. Cu-substitution improved the scaffold mechanical strength and the best result was observed in nHA.Cu5%/Cs/Gel scaffolds by the compressive strength 88.869 ± 19.574 MPa. Furthermore, 3% and 5% Cu-substituted nHA enhanced the scaffold structural stability and supported osteoblast spread, adhesion, survival, mineralization, and proliferation. Moreover, long-term and sustainable Cu release from scaffolds was observed within 28 days. Conclusion: Cu-substituted nHA/Cs/Gel scaffolds mimic the porous structure and mechanical strength of cancellous bone, along with prolonged degradation and Cu release, osteoblast attachment, viability, calcium deposition, and proliferation. Taken together, our results indicate the upgraded properties of nHA.Cu5%/Cs/Gel scaffolds for future applications in bone tissue engineering.