Osteochondral Repair and Electromechanical Evaluation of Custom 3D Scaffold Microstructured by Direct Laser Writing Lithography

Abstract

Objective The objective of this study was to assess a novel 3D microstructured scaffold seeded with allogeneic chondrocytes (cells) in a rabbit osteochondral defect model. Design Direct laser writing lithography in pre-polymers was employed to fabricate custom silicon-zirconium containing hybrid organic-inorganic (HOI) polymer SZ2080 scaffolds of a predefined morphology. Hexagon-pored HOI scaffolds were seeded with chondrocytes (cells), and tissue-engineered cartilage biocompatibility, potency, efficacy, and shelf-life in vitro was assessed by morphological, ELISA (enzyme-linked immunosorbent assay) and PCR (polymerase chain reaction) analysis. Osteochondral defect was created in the weight-bearing area of medial femoral condyle for in vivo study. Polymerized fibrin was added to every defect of 5 experimental groups. Cartilage repair was analyzed after 6 months using macroscopical (Oswestry Arthroscopy Score [OAS]), histological, and electromechanical quantitative potential (QP) scores. Collagen scaffold (CS) was used as a positive comparator for in vitro and in vivo studies. Results Type II collagen gene upregulation and protein secretion was maintained up to 8 days in seeded HOI. In vivo analysis revealed improvement in all scaffold treatment groups. For the first time, electromechanical properties of a cellular-based scaffold were analyzed in a preclinical study. Cell addition did not enhance OAS but improved histological and QP scores in HOI groups. Conclusions HOI material is biocompatible for up to 8 days in vitro and is supportive of cartilage formation at 6 months in vivo. Electromechanical measurement offers a reliable quality assessment of repaired cartilage.

Two-Photon Polymerization of 2.5D and 3D Microstructures Fostering a Ramified Resting Phenotype in Primary Microglia

“…The most significant limitation of 2PP is the relatively long printing time hindering the upscaling of the technology ( Moroni et al, 2018 ). Multiple polymeric, hydrogel or composite materials were employed in combination with 2PP to fabricate micro- and nano-patterns as well as 3D structures for in vitro cellular studies involving neuroblastoma, glioblastoma, prostate cancer, murine cerebellar granule, chondrocytes, macrophages, neuronal and stem cells ( Marino et al, 2013 ; Accardo et al, 2017 , 2018 ; Turunen et al, 2017 ; Maciulaitis et al, 2019 ; Fendler et al, 2019 ; Babi et al, 2021 ; Bertels et al, 2021 ; Maciulaitis et al, 2021 ; Nouri-Goushki et al, 2021 ; Akolawala et al, 2022 ; Costa et al, 2022 ).…”

Perspectives on Synthetic Materials to Guide Tissue Regeneration for Osteochondral Defect Repair

“…Strategies using this method have shown promise in tissue engineering . Recently, Maciulaitis et al utilized two-photon polymerization to form an osteochondral repair scaffold of a material deemed SZ2080 [consisting of 20% “inorganics” (i.e., methacryloxypropyl trimethoxysilane and zirconium propoxide) and 80% organics (i.e., 2-(dimethylamino)­ethyl methacrylate)] . The scaffold was designed with hexagonal pores, set at a diameter of 100 μm and height of 51 μm, displaying extremely precise morphological control.…”