ABSTRACT
BACKGROUND: A novel photocrosslinked fish collagen peptide-hyaluronic acid hydrogel has been successfully prepared by the research group. OBJECTIVE: To investigate the microstructure and the swelling properties in vitro of the photocrosslinked fish collagen peptide-hyaluronic acid hydrogel, and its histocompatibility and degradability in vivo. METHODS: A new photocrosslinked fish collagen peptide-hyaluronic acid hydrogel was prepared by photocrosslinking, and then divided into groups A (30 g/L), B (50 g/L) and C (100 g/L) according to the content of fish collagen peptide. The microstructure of the hydrogel was observed by scanning electron microscope and the swelling properties of hydrogels were studied by swelling test in vitro. Fifteen male Sprague-Dawley rats (provided by Qingdao Qinda Breeding Co., Ltd.) were selected, and three kinds of photocrosslinked fish collagen peptide-hyaluronic acid hydrogels were implanted into the back of rats. At 1, 2, 4, 6 and 8 weeks after surgery, three rats were selected for detecting the histocompatibility and biodegradability of hydrogels. The study was approved by the Ethics Committee of School of Basic Medicine, Qingdao University. RESULTS AND CONCLUSION: (1) With the increase of fish collagen peptide content, the transparency of hydrogel decreased and the pore size of hydrogel decreased. (2) Swelling equilibrium was achieved within 100 minutes in each group, and the swelling velocity and equilibrium swelling rate were inversely proportional to the content of collagen peptide. The equilibrium swelling rate was highest in the group A, which was 1 582%. (3) The hydrogel had good histocompatibility, mild inflammatory reaction, no infection, hematoma or other complications in vivo. (4) At 1 week after implantation, inflammatory cell infiltration was observed surrounding the hydrogels. The level of inflammatory cells peaked at 2 weeks, and then decreased gradually. The count of inflammatory cells was highest in the group A, followed by group B, and lowest in the group C (P group B > group C (P < 0.05). (6) These results indicate that photocrosslinked fish collagen peptide-hyaluronic acid hydrogel has good histocompatibility and biodegradability in vivo, which can be adjusted by the content of fish collagen peptides.
ABSTRACT
RESUMEN El quitosano (QT) es un biopolímero que ha sido ampliamente utilizado en aplicaciones de ingeniería de tejido óseo, demostrando un gran potencial para este propósito. El presente estudio tiene como objetivo desarrollar un sistema de hidrogel entrecruzable in situ, compuesto de quitosano y nano-partículas de hidroxiapatita (HAP), un equivalente al componente mineral del hueso. El quitosano fue modificado, utilizando reacciones de carbodiimida, con ácido lactobiónico y ácido azidobenzoico para hacerlo soluble a pH fisiológico y foto-entrecruzable, respectivamente. El quitosano modificado fue mezclado en diferentes proporciones con HAP, y luego de una corta exposición a luz UV, se formaron hidrogeles. Células madre mesenquimales de médula ósea de rata (MSC) fueron sembradas sobre estos hidrogeles y cultivadas por 4, 10 y 16 días, bajo condiciones osteogénicas y no-osteogénicas. A través de ensayos de proliferación celular, actividad de fosfatasa alcalina, y microscopía confocal, se observó que la mayoría de las formulaciones soportan la adhesión y proliferación celular, mostrando importantes interacciones célula-biomaterial, y una diferenciación osteogénica temprana destacada en las formulaciones 70:30 y 50:50, QT:HAP. Algunas formulaciones del sistema foto-entrecruzable tienen potencial en aplicaciones de ingeniería de tejido óseo, y se propone estudios más detallados de diferenciación celular.
ABSTRACT Chitosan (QT) is a biopolymer that has been used in widely used in bone tissue engineering applications, demonstrating great potential for that purpose. Therefore, the present study aims to develop an in situ crosslinking hydrogel system, composed of chitosan and hydroxyapatite (HAP). Briefly, chitosan was modified, using carbodiimide chemistry, with lactobionic and azidobenzoic acid to make it soluble at physiological pH and photo-crosslinkable, respectively. The modified chitosan was mixed with HAP, in different proportions, and later exposed to UV light, yielding hydrogels. Mesenchymal stem cells, from rat bone marrow, were seeded onto the hydrogels and cultured for 4, 10 and 16 days, under osteogenic and non-osteogenic conditions. Through cell proliferation and alkaline phosphatase activity assays, and confocal microscopy, it was observed that the majority of formulations supported cell adhesion and proliferation, and a significant early osteogenic differentiation in formulations 70:30 and 50:50, QT:HAP. According to these results, the proposed photo-crosslinking system has potential for tissue engineering applications, and further specific studies are proposed for cell differentiation.