Craniofacial bone defect repair with polymer scaffold and cell-derived matrix

Craniofacial defects can affect the area functions, strength, and aesthetics. While autograft has been used as gold standard to regenerate the tissue, the graft still has its drawbacks such as long operational time, limited tissue to harvest, donor site morbidity. Scientists have tried to overcome these by using tissue engineering and biomaterials. Poly(Glycerol sebacate) (PGS) is biocompatible and biodegradable. It’s not frequently used in bone tissue regeneration. Decellularised extracellular matrix (ECM) is rich in growth factors essential for various cell behaviours. However, repairing craniofacial defect only bony part can lead to scar formation or graft failure from soft tissue invasion [1-5]. PGS was used as an implantable scaffold aiming to support co-culture of tissue regeneration of both bone and soft tissue with an option of decellularised ECM. PGS scaffolds were fabricated by mixing various ratios of NaCl to polymer (2.5:1, 3.0:1, 3.5:1, 4.0:1, 4.5:1 w/w). After cross-linking at 120°C under vacuumed atmosphere for 24 hours, the salt was dissolved by submerging with deionised water. Human Telomerase Reverse Transcriptase mesenchymal stem cells (Y201) were cultured on these scaffolds for 14 days. All scaffolds could support Y201 attachment and growth similarly. A3.5 PGS was selected to seed with Y201 and culture for 21 days, cell matrix was then decellularised by incubating with 20 mM NH4OH + 0.5% Triton x-100 for 24 hours and DNAse-I for another 24 hours. After recellularisaiton with the new set of Y201, decellularised matrix on PGS didn’t enhance cell growth, differentiation or mineralisation when compared with PGS alone. Therefore PGS only was selected to move on to the next step; PGS scaffolds were seeded with Y201 and grown for 7 days before being flipped over and seeded with collagen and Human oral fibroblasts followed by (NOF343) and Human oral keratinocytes (FNB6) on top. The co-culture was grown for 10 days before being fixed, cryosectioned, and stained with H&E. A layer of Y201 matrix and a layer of NOF343 + FNB6 were observed on each side of PGS without any invasion noted. Therefore, PGS has a possible potential as an implantable scaffold in craniofacial tissue defect repair both bony and soft tissue part.