Electrospinning of nanofibrous polycaprolactone (PCL) and collagen-blended polycaprolactone for wound dressing and tissue engineering

Fabrication of nanofibrous biomaterials based on natural materials through various techniques is a popular research topic, particularly for biomedical applications. Electrospinning, a well-established technique for nanofiber production has also been extended for producing nanofibrous structures of natural materials that mimic natural extracellular matrix of mammalian tissues. Collagen nanofiber production utilizes hexafluoro propanol (HFP) as a solvent for electrospinning. A novel cost-effective electrospun nanofibrous membrane is established for wound dressing and allogeneic cultured epidermal substitute through the cultivation of human dermal keratinocytes for skin defects. Several synthetic polymers such as polycaprolactone (PCL) are generally electrospun for tissue engineering applications because of their remarkable mechanical stability and slow degradation rates. The large surface area of the polymer nanofibers with specific modifications facilitates cell adhesion and control of their cellular functions. The objectives of this study were to optimize fabrication parameters of electrospun nanofibrous membranes from biodegradable PCL and collagen-blended nanofibrous membranes to combine mechanical integrity and spinnability of PCL with high biocompatibility of collagen, and to examine keratinocyte attachment, morphology, proliferation, and cell-matrix interactions. Results prove that the porous nanofibrous PCL and modified PCL-blended collagen nanofibrous membranes are suitable for the attachment and proliferation of keratinocytes, and might have the potential to be applied as wound dressing as well as in tissue engineering as an epidermal substitute for the treatment of skin defects and burn wounds

Doku mühendisliği yöntemi ile kollajen ve nacmc kullanılarak çift katmanlı deri modeli oluşturulması

TÜBİTAK MAG01.05.2015TÜBİTAK tarafından desteklenen bu çalışmada, insan derisini taklit etmek amacıyla, gözenekli kollajen ve sodyum karboskimetilselüloz (NaCMC) iskeleler kullanılarak iki katmanlı deri modelleri başarıyla üretilmiştir. Geliştirilen deri modelinde, gözenekli kollajen iskelenin dış katman olan epidermal tabakasını, ve gözenek boyutu dış katmana göre daha büyük olan NaCMC iskelenin ise iç katman olan dermal tabakayı oluşturması planlanmıştır. Hazırlanan iskeleler, sulu ortamda dayanıklı olabilmelerini sağlamak amacıyla dehidrotermal (DHT) işlem ile ve/veya gluteraldehit ile çapraz bağlanmıştır. En uygun çapraz bağlama yöntemine karar vermek için, iskelelerin bozunma hızları ve mekanik direnç ve dayanımları analiz edilmiştir. Süngerimsi yapıdaki kollajen ve NaCMC iskeleler, kalınlık, yüzey gözenekliliği, kütle gözenekliliği, gözenek boyutu dağılımı, in situ ve enzimatik ortamdaki bozunma hızları, basma testi ile mekanik güçleri, FTIR-ATR ile kimyasal yapıları ve SEM ile topografyaları incelemiş ve özellikleri karakterize edilmiştir. Dış̧ tabakayı oluşturan küçük gözenekli kollajen iskelenin üzerine insan kökenli keratinosit hücreleri, alt tabakayı oluşturan büyük porlu NaCMC iskelenin üzerine insan dermal fibroblastları ekilmiş ve ko-kültivasyon yapılmıştır. İskelelerin insan dermal keratinositleri ve insan dermal fibroblastları ile olan in vitro etkileşimleri hücre kültür çalışmalarıyla değerlendirilmiştir. Sonuç olarak, üretilen çift tabakalı iskelelerin çapraz bağlama metodunun geliştirilmesi sonucunda deri doku mühendisliği uygulamaları için potansiyel bir alternatif model olarak kabul edilebileceği gösterilmiştir.In this study supported by TÜBİTAK, bilayer scaffolds of porous collagen and sodium carboxymethyl cellulose were succesfully prepared to mimic human skin. In this model skin that was developed, porous collagen served as the external component, the epidermal layer, and the NaCMC scaffold with larger pores than the exterior as the inner, dermal layer. In order to render the scaffolds stable in aqueous media they were crosslinked with the dehydrothermal (DHT) process and/or with glutaraldehyde. In order to decide on the optimum crosslinkage procedure the degradation rate and mechanical resistance and strength were analyzed. The sponge-like collagen and NaCMC scaffolds were examined and characterized. for their thickness, surface porosity, bulk porosity, pore size distribution, in situ and enzymatic degradation rates, with compression tests for their mechanical properties, with FTIR-ATR for their chemical structure, and with SEM for their topography Human keratinocytes were seeded on small pore sized collagen scaffold that represented the external layer and human dermal fibroblasts were seeded on the larger pore sized lower, NaCMC, layer, and co-cultured. The in vitro interactions of the human dermal keratinocytes and human dermal fibroblasts were assessed with cell culture studies. As a result it was demonstrated that the bilayer scaffold manufactured after the development of a crosslinking method could be accepted as an alternative model system for skin tissue engineering applications