ZIF-8-modified hydrogel sequentially delivers angiogenic and osteogenic growth factors to accelerate vascularized bone regeneration.

To realize high-quality vascularized bone regeneration, we developed a multifunctional hydrogel (SHPP-ZB) by incorporating BMP-2@ZIF-8/PEG-NH nanoparticles (NPs) into a sodium alginate/hydroxyapatite/polyvinyl alcohol hydrogel loaded with PDGF-BB, allowing for the sequential release of angiogenic and osteogenic growth factors (GFs) during bone repair. ZIF-8 served as a protective host for BMP-2 from degradation, ensuring high encapsulation efficiency and long-term bioactivity. The SHPP-ZB hydrogel exhibited enhanced mechanical strength and injectability, making it suitable for complex bone defects.

Integrated gradient tissue-engineered osteochondral scaffolds: Challenges, current efforts and future perspectives.

The osteochondral defect repair has been most extensively studied due to the rising demand for new therapies to diseases such as osteoarthritis. Tissue engineering has been proposed as a promising strategy to meet the demand of simultaneous regeneration of both cartilage and subchondral bone by constructing integrated gradient tissue-engineered osteochondral scaffold (IGTEOS). This review brought forward the main challenges of establishing a satisfactory IGTEOS from the perspectives of the complexity of physiology and microenvironment of osteochondral tissue, and the limitations of obtaining the desired and required scaffold.

Bone-like hydroxyapatite anchored on alginate microspheres for bone regeneration.

Inspired by the initial mineralization process in bone matrix vesicles (MVs), we used Dulbecco's Modified Eagle's Medium (DMEM) to establish the similar physiological environment to that in MVs for biomimetic mineralization on alginate (ALG) microspheres. The results showed that HA crystals were firstly formed and anchored on the membrane of microspheres like the initial deposition of hydroxyapatite crystals inside MVs. With the continuous growth and accumulation of mineral crystals, HA coating was finally formed on ALG microspheres.

Effective elastic modulus of an intact cornea related to indentation behavior: A comparison between the Hertz model and Johnson-Kendall-Roberts model.

In this study, a macro-indentation test on the submillimeter scale was performed to analyze the indentation behavior of an intact cornea under physiological pressures. The Hertz and Johnson-Kendall-Roberts (JKR) models were employed to solve the elastic modulus (E) of the intact cornea. The relevant detailed analysis showed that the JKR model, which accounted for the contribution from the adhesion energy, could be used to obtain the E values that were more than two-folds of those obtained from the Hertz model, which only considered the external force.

Alginate microgels as delivery vehicles for cell-based therapies in tissue engineering and regenerative medicine.

Conventional stem cell delivery typically utilize administration of directly injection of allogenic cells or domesticated autogenic cells. It may lead to immune clearance of these cells by the host immune systems. Alginate microgels have been demonstrated to improve the survival of encapsulated cells and overcome rapid immune clearance after transplantation.

Electrospun polyamide-6/chitosan nanofibers reinforced nano-hydroxyapatite/polyamide-6 composite bilayered membranes for guided bone regeneration.

Periodontal defect poses a significant challenge in orthopedics. Guided Bone Regeneration (GBR) membrane is considered as one of the most successful methods applied to reconstruct alveolar bone and then to achieve periodontal defect repair/regeneration. In this paper, a novel polyamide-6/chitosan@nano-hydroxyapatite/polyamide-6 (PA6/CS@n-HA/PA6) bilayered tissue guided membranes by combining a solvent casting and an electrospinning technique was designed.

Coated electrospun polyamide-6/chitosan scaffold with hydroxyapatite for bone tissue engineering.

Polyamide-6 (PA6) is a synthetic polymer that bears resemblance to collagen in its backbone and has excellent stability in human body fluid. Chitosan (CS) with the similar structure to that of the polysaccharides existing in the extracellular matrix (ECM), has a more suitable biodegradation rate for the formation of new-bone. Electrospun fiber have nanoscale structure, high porosity and large specific surface area, can simulate the structure and biological function of the natural ECM.

Application of electrospun nanofibers in bone, cartilage and osteochondral tissue engineering.

Tissue damage related to bone and cartilage is a common clinical disease. Cartilage tissue has no blood vessels and nerves. The limited cell migration ability results in low endogenous healing ability.

Mineralized Polyamide66/Calcium Chloride Nanofibers for Bone Tissue Engineering.

This study aimed at designing a novel electrospun scaffolding material that structurally and chemically resembles native extracellular matrix for bone tissue engineering. Calcium chloride-complexed polyamide66 (PA66/CaCl) and pure PA66 electrospun nanofibers were fabricated by the electrospinning method. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared (FTIR) spectroscopy were used to investigate the effect of the presence of ionized salt in the polymer solution on the mechanical properties and other properties of the electrospun scaffolds.