Increased mucociliary differentiation and aquaporins formation of respiratory epithelial cells on retinoic acid-loaded hyaluronan-derivative membranes
Introduction
While forming a continuous lining of the airway interacting with the environment, the respiratory epithelium acts as a physical and functional barrier to external deleterious agents, subsequently preventing infection via escalation of the mucociliary system. The latter, including ciliated respiratory epithelium, mucous blanket and periciliary fluid, serves as an important defense mechanism in the respiratory system. Therefore, restoration of mucociliary function is important in sinonasal surgery as well as in respiratory tract reconstruction. Clinically, several biomaterials are adopted in the respiratory and sinonasal surgery to control bleeding, facilitate wound healing and prevent synechia [1], [2]. As conventional biomaterials damage the nasal mucosa with loss of ciliated mucosal surface [3], developing biomaterials that can facilitate mucociliary restoration of the respiratory epithelium is a priority concern.
As is well known, vitamin A is essential for maintaining the mucociliary epithelium in the conducting airways [4], [5], [6]. Chronic vitamin A deficiency leads to replacement of the mucociliary epithelium by a stratified squamous epithelium. Also, systematically administering vitamin A facilitates the regeneration of normal ciliated respiratory epithelium [7]. In vitro studies with organs and primary respiratory epithelial cells (RECs) have established that without retinoic acid (RA), the cultures undergo squamous differentiation and that adding vitamin A to the medium restores mucous differentiation [4], [8], [9], [10]. However, despite being a powerful biological agent, RA is generally not used in regenerative medicine due to its scarce bioavailability via conventional administration [11]. For instance, providing RA continuously to local sinonasal tissue to promote mucociliary differentiation of RECs is rather difficult. Therefore, if RA is slowly released from biomaterials, RA-loaded biomaterials can serve as a novel biomaterial allowing for continuous influence of cellular behavior.
Earlier studies have demonstrated that hyaluronan-derivative membranes (HAm) can provide a more preferential environment for mucociliary differentiation of RECs than collagen [12], [13]. The ability to use HAm loaded with RA for respiratory and sinonasal surgery may facilitate the restoration of mucociliary differentiation of RECs. However, whether RA loaded in HAm can stimulate mucociliary and aquaporins (AQP), differentiation of RECs remains unexplored. In this study, we attempt to develop RA-loaded hyaluronan-derivative membranes (RA-HAm) and investigate their effect in mucociliary and AQP differentiation of RECs.
Section snippets
Preparation of RA-HAm
180 mg of HYAFF (Fidia Advanced Biomaterials, Italy), which was an esterified form of hyaluronan, was dissolved in 1 ml of dimethyl sulfoxide (DMSO) at room temperature. DMSO was pre-filtered through a 0.22 μm Teflon pre-filter (Millipore, Billerica, USA) and the procedure was conducted in the dark hood. 10 μl of RA at 10−3 M in ethanol was added to this solution and mixed well. This solution was then spread on the culture surface at 150 μl cm−2. Ethanol was added in the proportion of 100 times the
In vitro study of RA release
The initial concentration of RA in RA-HAm dissolved in 500 μl DMSO was 42 μM, as detected by the ELISA reader. Therefore, the amount of RA loaded in RA-HAm was 6.3 μg (42 μM × 500 μl × 300 g mol−1) and then a fast release was observed on the first day followed by a slow release. The remaining RA in membranes was maintained for 7 days (Fig. 1A). The cumulative release rate of RA from supportive biomaterials was ∼87% under detect limitation at the seventh day (Fig. 1B).
Proliferation and viability of RECs on RA-HAm vs. HAm
After contacting biomaterials, cells
Discussion
As is well known, retinoids and other derivatives of vitamin A regulate cell proliferation, differentiation and morphogenesis. The effects of retinoids are mediated by nuclear receptors, e.g., retinoic acid receptors and retinoic X receptors which can activate or repress transcription of numerous target genes [19], [20]. In addition to playing a major role in maintaining the mucociliary phenotype of RECs, retinoids are critical determinants of their normal function. In vivo, vitamin A
Conclusions
This study represents a model for releasing hydrophobic RA from hyaluronan-derivative biomaterials. Incorporating RA into hyaluronan-derivative membranes can promote mucociliary differentiation and AQP differentiation of RECs. We believe that RA-loaded hyaluronan biomaterials are highly promising biomaterials for use in sinonasal surgery and tissue engineering of respiratory system in the near future.
Acknowledgements
The authors would like to thank the National Science Council of Taiwan (No. NSC-98-2314-B-418-001-MY3) for financially supporting this work.
References (33)
- et al.
Poly(lactic-co-glycolicacid) electrospun fibrous meshes for the controlled release of retinoic acid
Acta Biomater
(2010) - et al.
Increased mucociliary differentiation of human respiratory epithelial cells on hyaluronan-derivative membranes
Acta Biomater
(2010) - et al.
Regulation of ciliary differentiation of human respiratory epithelial cells by the receptor for hyaluronan-mediated motility on hyaluronan-based biomaterials
Biomaterials
(2010) Rapid colorimetric assay for cellular growth and survival: application of proliferation and cytotoxicity assays
J Immunol Methods
(1983)- et al.
The nuclear receptor superfamily: the second decade
Cell
(1995) - et al.
On the importance and mechanisms of burst release in matrix-controlled drug delivery systems
J Control Release
(2001) - et al.
Semisynthetic resorbable materials from hyaluronan esterification
Biomaterials
(1998) - et al.
All-trans retinoic acid inhibits proliferation of intestinal epithelial cells by inhibiting expression of the gene encoding Kruppel-like factor 5
FEBS Lett
(2004) - et al.
Aquaporins: water channel proteins of the cell membrane
Prog Histochem Cytochem
(2004) - et al.
All-trans retinoic acid increases expression of aquaporin-5 and plasma membrane water permeability via transactivation of Sp1 in mouse lung epithelial cells
Biochem Biophys Res Commun
(2006)
Biomaterials for sinus implantation
Curr Opin Otolaryngol Head Neck Surg
Absorbable biomaterials used within paranasal sinuses: an animal study
Am J Rhinol
Effect of packing on nasal mucosa of sheep
J Laryngol Otol
Effects of vitamin A-deprivation on hamster tracheal epithelium. A quantitative morphologic study
Virchows Arch B Cell Pathol Incl Mol Pathol
Restoration of mucociliary tracheal epithelium following deprivation of vitamin A. A quantitative morphologic study
Virchows Arch B Cell Pathol Incl Mol Pathol
An electron microscopic study of metaplasia of the rat tracheal epithelium in vitamin A deficiency
Lab Invest
Cited by (9)
The Fabrication and in vitro Evaluation of Retinoic Acid-Loaded Electrospun Composite Biomaterials for Tracheal Tissue Regeneration
2020, Frontiers in Bioengineering and BiotechnologyHyaluronan antagonizes the differentiation effect of TGF-β1 on nasal epithelial cells through down-regulation of TGF-β type I receptor
2018, Artificial Cells, Nanomedicine and BiotechnologyChitosan promotes aquaporin formation and inhibits mucociliary differentiation of nasal epithelial cells through increased TGF-β1 production
2017, Journal of Tissue Engineering and Regenerative MedicineRetinoic Acid-Loaded Collagen-Hyaluronate Scaffolds: A Bioactive Material for Respiratory Tissue Regeneration
2017, ACS Biomaterials Science and Engineering