Collagen-chitosan-hydroxyapatite composite scaffolds for bone repair in ovariectomized rats

Abstract

Lesions with bone loss may require autologous grafts, which are considered the gold standard; however, natural or synthetic biomaterials are alternatives that can be used in clinical situations that require support for bone neoformation. Collagen and hydroxyapatite have been used for bone repair based on the concept of biomimetics, which can be combined with chitosan, forming a scaffold for cell adhesion and growth. However, osteoporosis caused by gonadal hormone deficiency can thus compromise the expected results of the osseointegration of scaffolds. The aim of this study was to investigate the osteoregenerative capacity of collagen (Co)/chitosan (Ch)/hydroxyapatite (Ha) scaffolds in rats with hormone deficiency caused by experimental bilateral ovariectomy. Forty-two rats were divided into non-ovariectomized (NO) and ovariectomized (O) groups, divided into three subgroups: control (empty defect) and two subgroups receiving collagen/chitosan/hydroxyapatite scaffolds prepared using different methods of hydroxyapatite incorporation, in situ (CoChHa1) and ex situ (CoChHa2). The defect areas were submitted to macroscopic, radiological, and histomorphometric analysis. No inflammatory processes were found in the tibial defect area that would indicate immune rejection of the scaffolds, thus confirming the biocompatibility of the biomaterials. Bone formation starting from the margins of the bone defect were observed in all rats, with a greater volume in the NO groups, particularly the group receiving CoChHa2. Less bone formation was found in the O subgroups when compared to the NO. In conclusion, collagen/chitosan/hydroxyapatite scaffolds stimulate bone growth in vivo but abnormal conditions of bone fragility caused by gonadal hormone deficiency may have delayed the bone repair process.

Chitosan as a Polyfunctional Crosslinker for a Renewable-Based Resorcinol Diglycidyl Ether

“…It is important to mention the enzymatic degradation of chitosan and chitosan-based therapeutic systems, being resorbable in situ for medical applications. At the same time, chitosan presents other degradation mechanisms, such as oxidation with H 2 O 2 , acid hydrolysis with HCl, ultrasonic irradiation, where 1–4 bonds can be broken in the amorphous fields, and also by applying heat or microwave. , This most important derivative of chitin is a versatile biopolymer showing biocompatibility, nontoxicity, and antibacterial and antifungal properties. , That is why it is used in several biomedical applications: wound healing, encapsulation of sensitive drugs, drug delivery, and scaffolds for nerve tissue regeneration. − Chuc-Gamboa et al compared the effects on biocompatibility of two scaffolds based on chitosan crosslinked with polyethylene glycol diglycidyl ether (PEGDE) and glutaraldehyde (GA). PEGDE-crosslinked chitosan showed a reduction in free amino groups and in the amide I/II ratio, indicating that PEGDE used in low concentrations is a biocompatible crosslinker for chitosan, and therefore, these materials can be used in bone regeneration applications.…”

Worldwide trends on hydroxyapatite from animal waste for biomedical applications – a bibliometric analysis (2012-2022)

“…Due to the shortage of donors worldwide [6] and the threat of infection [7], autograft and allograft are not practical options for bone substitutes. Abundantly available and environmentally friendly hydroxyapatite has biological similarities to bone tissue [8][9][10][11], making it an attractive option for hard tissue engineering and biomedical engineering research [12]. Waste from animals, for instance mammalian bone [13][14][15], fish bones and scales [16][17][18], and shells [19][20][21], can be used to extract hydroxyapatite and develop artificial bone substitutes.…”