Nasal fibroblast conditioned medium promotes cell attachment and migration of human respiratory epithelium

Endoscopic sinus surgery (ESS) is a well-known surgical treatment for chronic rhinosinusitis disease after failed medical and antibiotics treatment. However, improper wound healing might induce synechiae or adhesion. Conditioned medium from cultured cells is known to promote wound healing and potentially able to accelerate wound healing in ESS and other airway epithelial injuries. This study was to investigate the effect of human nasal fibroblast conditioned medium on the attachment, proliferation and migration of respiratory epithelial cells (RECs) in an in vitro model. RECs and fibroblasts were co-cultured in Defined Keratinocytes Medium and F-12 and Dulbecco’s Modified Eagle’s Medium. Once confluent, the fibroblasts were removed, leaving the colonies of RECs to reach confluency. RECs and fibroblasts were cultured separately and the conditioned medium was acquired by culturing fibroblast either in DKSFM or F12: DMEM, denoted as NFCM_DKSFM and NFCM_FD, respectively. RECs were supplemented with 20% conditioned medium for attachment, proliferation and migration assay. The results showed significantly higher cell attachment in NFCM_DKSFM (3452.77±588.1 cell/cm2) compared to NFCM_FD (2336.1±440.4 cell/cm2) and DKSFM alone (2819.8±509.5 cell/cm2). After 7 days, the specific growth rate was higher in DKSFM (0.019±5.16×10-4 h-1) compared to NFCM_DKSFM (0.015±8.94×10-4 h-1) and NFCM_FD (0.013±1.03×10-3 h-1). The mean of migration rate was significantly higher in NFCM_DKSFM (4341.81±385.7 μm2/hr) compared to NFCM_FD (1803.38±408.1 μm2/hr) and DKSFM (1933.48±271.9 μm2/hr). Hence, NFCM_DKSFM supplementation provides suitable culture conditions for RECs through increased cell attachment and migration, which suggest that the factors secreted in conditioned medium may play a major role in enhancing airway epithelial wound healing

Neurogenic differentiation potential of human nasal mucosa obtained from the middle and inferior turbinates

Olfactory bulb and nasal mucosa are one of the sources for neural stem cell, including the superior and middle turbinates (MT). The middle and inferior turbinates (IT) provides the largest area of nasal mucosa which is technically easier to harvest the stem cell for future transplantation. The ability of nasal respiratory epithelial cells (RECs) and nasal fibroblasts (NFs) from both middle and inferior turbinates to differentiate into neural lineage (NL) cells were compared in this study. Six redundant human MT and IT from post-sinus surgery were digested and cultured. The RECs and NFs were separated and induced with neurotrophic factors of forskolin, human basic fibroblast growth factor (bFGF), platelet-derived growth factor-AA (PDGF-AA) and heregulin-β1-EGF-domain. Based on immunocytochemistry and quantitative PCR, the NL induced NFs of MT expressed GFAP, Nestin and P75 receptor. NL induced RECs from MT and IT expressed GFAP and Nestin but did not express the P75 receptor protein. Regarding the control, the non-induced RECs and fibroblasts expressed Nestin only. This study demonstrated that nasal mucosa cells from both IT and MT have the potential to differentiate into neural lineage cells even though the fibroblasts of MT are superior in term of quality. Hopefully, these tissues will provide better donor area with less morbidity for autologous or allograft transplantation in future neural regenerative medicine

Preliminary Study on the Development of In Vitro Human Respiratory Epithelium Using Collagen Type I Scaffold as a Potential Model for Future Tracheal Tissue Engineering

Pathological conditions of the tracheal epithelium, such as postoperative injuries and chronic conditions, often compromise the functionality of the respiratory epithelium. Although replacement of the respiratory epithelium using various types of tracheal transplantation has been attempted, there is no predictable and dependable replacement method that holds for safe and practicable long-term use. Therefore, we used a tissue engineering approach for ex vivo regeneration of the respiratory epithelium (RE) construct. Collagen type I was isolated from sheep tendon and it was fabricated in a three-dimensional (3D) scaffold format. Isolated human respiratory epithelial cells (RECs) and fibroblasts from nasal turbinate were co-cultured on the 3D scaffold for 48 h, and epithelium maturation was allowed for another 14 days in an air–liquid interface culture system. The scanning electron microscope results revealed a fabricated porous-structure 3D collagen scaffold. The scaffold was found to be biocompatible with RECs and fibroblasts and allows cells attachment, proliferation, and migration. Immunohistochemical analysis showed that the seeded RECs and fibroblasts were positive for expression of cytokeratin 14 and collagen type I markers, respectively, indicating that the scaffold supports the native phenotype of seeded cells over a period of 14 days. Although a longer maturation period is needed for ciliogenesis to occur in RECs, the findings suggest that the tissue-engineered RE construct is a potential candidate for direct use in tracheal epithelium replacement or tracheal tube reengineering

Recent Approaches to the Modification of Collagen Biomatrix as a Corneal Biomatrix and Its Cellular Interaction

Over the last several decades, numerous modifications and advancements have been made to design the optimal corneal biomatrix for corneal epithelial cell (CECs) or limbal epithelial stem cell (LESC) carriers. However, researchers have yet to discover the ideal optimization strategies for corneal biomatrix design and its effects on cultured CECs or LESCs. This review discusses and summarizes recent optimization strategies for developing an ideal collagen biomatrix and its interactions with CECs and LESCs. Using PRISMA guidelines, articles published from June 2012 to June 2022 were systematically searched using Web of Science (WoS), Scopus, PubMed, Wiley, and EBSCOhost databases. The literature search identified 444 potential relevant published articles, with 29 relevant articles selected based on inclusion and exclusion criteria following screening and appraising processes. Physicochemical and biocompatibility (in vitro and in vivo) characterization methods are highlighted, which are inconsistent throughout various studies. Despite the variability in the methodology approach, it is postulated that the modification of the collagen biomatrix improves its mechanical and biocompatibility properties toward CECs and LESCs. All findings are discussed in this review, which provides a general view of recent trends in this field