Co-culture of corneal epithelial cells and adipose stem cells - towards the use of hydrogels in ocular surface reconstruction

Objectives: In a tissue engineering field, co-culture techniques of different kind have been widely researched in recent years to form physiologically relevant cell structures for different tissue reconstructions. The treatment methods of that kind are promising opportunity to be used also in the treatment of corneal blindness, which is still mainly treated with traditional tissue graft from a donor. Tissue grafts cannot still be used to treat one of the most common cause behind the corneal blindness -limbal stem cell deficiency (LSCD), due the lack of host stem cells. Thus, alternative opportunities are needed. Objectives of this research were to find a suitable medium for human adipose stem cells (hASCs), from those that had already been shown to be suitable for human corneal epithelial cells (hCECs), and use it to co-culture hydrogel- embedded hASCs with hCECs. Results will possibly help us to evaluate the functionality of this kind of 3D structure better as a treatment method of the corneal damages and LSCD. Materials and methods: HASCs were first cultured in three different mediums to find a suitable one to use in co-culturing. Following 2D co-culturing occurred within indirect- and direct contact between the immortalized hCECs and hASCs. Research was accomplished by culturing the hASCs inside the hyaluronic acid- hydrogel. Cells' behaviour during these experiments was evaluated with phase-contrast microscope, proliferation- and live/dead assays and immunofluorescent stainings. Results and conclusions: HASCs grew well in tested co-culture medium and appeared to have enhancing effect on the growth and differentiation of the co-cultured immortalized hCECs. When cultured in 3D hydrogel structure, hASCs were able to survive and proliferate within right cell densities. These results indicate that 3D co-cultures with hCECs and hydrogel- embedded hASCs might have potential for future applications in ocular surface reconstruction

Clinical Study of Nanofibrillar Cellulose Hydrogel Dressing for Skin Graft Donor Site Treatment

Objective: Skin graft donor site management is a concern particularly for elderly patients and patients with poor wound healing competence, and also because donor sites are a source of pain and discomfort. Although different types of dressings exist, there is no consensus regarding optimal dressing type on donor site care to promote healing, reduce pain, and improve patients' comfort. Approach: This prospective, single-center clinical trial evaluated the performance of nanofibrillar cellulose (NFC) wound dressing (FibDex (R) by UPM-Kymmene Corporation) for treatment of donor sites compared with a polylactide-based copolymer dressing. The study enrolled 24 patients requiring skin grafting with mean age of 49 +/- 18. The primary outcome measure was wound healing time. Secondary outcomes, the epithelialization, subjective pain, the scar appearance assessed using the Patient and Observer Scar Assessment Scale (POSAS), and skin elasticity and transepidermal water loss (TEWL), were evaluated at 1 and 6 months postoperatively. Results: No statistically significant differences were observed between NFC and copolymer dressings regarding wound healing time, epithelialization, experience of pain, or TEWL. Significant differences were observed in the POSAS results for thickness and vascularity in the Observer score, in the favor of NFC over copolymer dressing. Moreover, skin elasticity was significantly improved with NFC dressing in terms of viscoelasticity and elastic modulus at 1 month postoperatively. Innovation: NFC dressing is a new, green sustainable product for wound treatment without animal or human-origin components. Conclusion: NFC dressing provides efficient wound healing at skin graft donor sites and is comparable or even preferable compared with the copolymer dressing.Peer reviewe

Nanofibrillar cellulose wound dressing supports the growth and characteristics of human mesenchymal stem/stromal cells without cell adhesion coatings

Abstract Background In the field of regenerative medicine, delivery of human adipose-derived mesenchymal stem/stromal cells (hASCs) has shown great promise to promote wound healing. However, a hostile environment of the injured tissue has shown considerably to limit the survival rate of the transplanted cells, and thus, to improve the cell survival and retention towards successful cell transplantation, an optimal cell scaffold is required. The objective of this study was to evaluate the potential use of wood-derived nanofibrillar cellulose (NFC) wound dressing as a cell scaffold material for hASCs in order to develop a cell transplantation method free from animal-derived components for wound treatment. Methods Patient-derived hASCs were cultured on NFC wound dressing without cell adhesion coatings. Cell characteristics, including cell viability, morphology, cytoskeletal structure, proliferation potency, and mesenchymal cell and differentiation marker expression, were analyzed using cell viability assays, electron microscopy, immunocytochemistry, and quantitative or reverse transcriptase PCR. Student’s t test and one-way ANOVA followed by a Tukey honestly significant difference post hoc test were used to determine statistical significance. Results hASCs were able to adhere to NFC dressing and maintained high cell survival without cell adhesion coatings with a cell density-dependent manner for the studied period of 2 weeks. In addition, NFC dressing did not induce any remarkable cytotoxicity towards hASCs or alter the morphology, proliferation potency, filamentous actin structure, the expression of mesenchymal vimentin and extracellular matrix (ECM) proteins collagen I and fibronectin, or the undifferentiated state of hASCs. Conclusions As a result, NFC wound dressing offers a functional cell culture platform for hASCs to be used further for in vivo wound healing studies in the future

Effects of nanofibrillated cellulose hydrogels on adipose tissue extract and hepatocellular carcinoma cell spheroids in freeze-drying

The aim of this study was to evaluate the effects of two nanofibrillated cellulose (NFC) hydrogels on two human derivatives during freeze-drying. Native NFC hydrogel is a suitable platform to culture 3D cell spheroids and a hydrogel processed further, called anionic NFC (ANFC) hydrogel, is an excellent platform for controlled release of proteins. Moreover, it has been shown to be compatible with freeze-drying when correct lyoprotectants are implemented. Freeze-drying is a method, where substance is first frozen, and then vacuum dried trough sublimation of water in order to achieve dry matter without the loss of the original three-dimensional structures. The first chosen human derivative was adipose tissue extract (ATE) which is a cell-free growth factor-rich preparation capable of promoting growth of regenerative cells. The release of growth factors from the freeze-dried mixture of ATE and ANFC was compared to that of non-freeze-dried control mixtures. The release profiles remained at the same level after freeze-drying. The second derivative was hepatocellular carcinoma (HepG2) cell spheroids which were evaluated before and after freeze-drying. The 3D structure of the HepG2 cell spheroids was preserved and the spheroids retained 18% of their metabolic activity after rehydration. However, the freeze-dried and rehydrated HepG2 cell spheroids did not proliferate and the cell membrane was damaged by fusion and formation of crystals.Peer reviewe

Co-culture of corneal epithelial cells and adipose stem cells - towards the use of hydrogels in ocular surface reconstruction

Objectives: In a tissue engineering field, co-culture techniques of different kind have been widely researched in recent years to form physiologically relevant cell structures for different tissue reconstructions. The treatment methods of that kind are promising opportunity to be used also in the treatment of corneal blindness, which is still mainly treated with traditional tissue graft from a donor. Tissue grafts cannot still be used to treat one of the most common cause behind the corneal blindness -limbal stem cell deficiency (LSCD), due the lack of host stem cells. Thus, alternative opportunities are needed. Objectives of this research were to find a suitable medium for human adipose stem cells (hASCs), from those that had already been shown to be suitable for human corneal epithelial cells (hCECs), and use it to co-culture hydrogel- embedded hASCs with hCECs. Results will possibly help us to evaluate the functionality of this kind of 3D structure better as a treatment method of the corneal damages and LSCD. Materials and methods: HASCs were first cultured in three different mediums to find a suitable one to use in co-culturing. Following 2D co-culturing occurred within indirect- and direct contact between the immortalized hCECs and hASCs. Research was accomplished by culturing the hASCs inside the hyaluronic acid- hydrogel. Cells' behaviour during these experiments was evaluated with phase-contrast microscope, proliferation- and live/dead assays and immunofluorescent stainings. Results and conclusions: HASCs grew well in tested co-culture medium and appeared to have enhancing effect on the growth and differentiation of the co-cultured immortalized hCECs. When cultured in 3D hydrogel structure, hASCs were able to survive and proliferate within right cell densities. These results indicate that 3D co-cultures with hCECs and hydrogel- embedded hASCs might have potential for future applications in ocular surface reconstruction