Advances in cartilage repair: The influence of inorganic clays to improve mechanical and healing properties of antibacterial Gellan gum-Manuka honey hydrogels

Evaluation of Nisin and LL-37 Antimicrobial Peptides as Tool to Preserve Articular Cartilage Healing in a Septic Environment

“…Stem cells were seeded in 24 well plates at a density of 1x10 4 cells/well for 24 h to allow adhesion and spreading. Then, 1 ml of the chondrogenic medium (DMEM High Glucose (4.5 g/L) supplemented with 10% ITS+1 Premix Tissue Culture Supplement, 10 −7 M dexamethasone, 1 µM ascorbate-2-phosphate, 1% sodium pyruvate and 10 ng/mL transforming growth factor-beta 1 (TGF-β1), all from Merck, Milan, Italy) (Bonifacio et al, 2018(Bonifacio et al, , 2020 was added supplemented with 75 µg/ml of Nisin or 10 µg/ml of LL-37. The AMPs-free medium was considered as a control.…”

“…The AMPs targeted antimicrobial activity was investigated in cocultures by using 3D spheroids and S. aureus as a reference strain for articular cartilage infections as we have previously shown (Bonifacio et al, 2018(Bonifacio et al, , 2020. Briefly, spheroids were allowed to equilibrate for 48 h in the complete medium; then, the medium was replaced by 1 ml of the antibiotic-free DMEM containing 1 × 10 5 bacteria.…”

“…Biomaterials science recently offered an alternative approach for articular cartilage repair based on the possibility to replace the injured tissue by an artificial scaffold substitute resembling the naïve tissue, thus allowing for temporary replacement and a progressive guided self-repair. Some promising examples include the use of hydrogels (Cochis et al, 2017;Cipriani et al, 2019;Bonifacio et al, 2020;Meng et al, 2020), polymers (Pourbashir et al, 2020;Xuan et al, 2020), and composites (Gao et al, 2019;Sun et al, 2019). However, the scaffold synthesis and surgical procedures aimed at the scaffold implantation open the possibility of bacterial infection.…”

Enhancing Mechanical Properties and Biological Performances of Injectable Bioactive Glass by Gelatin and Chitosan for Bone Small Defect Repair

“…Moreover, they are representative for compositions holding or chitosan (b) or gelatin (d) in combination with BG and GPTMS (wt20%) in order to better understand a possible role of the polymers in promoting or interfering with osteogenesis over the intrinsic BG’s pro-osteogenic properties. Accordingly, mesenchymal stem cells (hMSC) were seeded into the pores of the composites and maintained in conservative medium (DMEM 15% FBS 1% antibiotics); the use of osteogenic chemicals such as dexamethasone and β-glycerophosphate was voluntarily prevented in order to exploit BG bioactivity [ 49 ] and to evaluate a possible further contribution of the polymers. This choice was also due to the need of applying collagen as temporary substrate for cell maintenance within the pores of the scaffold using static conditions; in fact, collagen can result in promoting osteogenesis, thus somehow influencing results.…”

“…After the evaluation of specimens’ cytocompatibility and antibacterial activity, the following composites were selected as the most promising and used for further analysis: b (BG-Cn-GPTMS20) and d (BG-Gel-GPTMS20). Accordingly, they were used to test cells’ ability to grow within specimens’ pores simulating a 3D matrix [ 48 , 49 ]. First, hMSC were mixed in a defined number (1 × 10 6 ) into 50 µL of a liquid collagen matrix (PureCol™ EZ Gel solution, from Sigma); then, the collagen loading cells were slowly added dropwise into the composites at room temperature (liquid phase) to completely fill their pores.…”