Preparation of Collagen/Hydroxyapatite Composites Using the Alternate Immersion Method and Evaluation of the Cranial Bone-Forming Capability of Composites Complexed with Acidic Gelatin and b-FGF

Abstract

Bone-substitute materials are essential in dental implantology. We prepared collagen (Col)/hydroxyapatite (Hap)/acidic gelatin (AG)/basic fibroblast growth factor (b-FGF) constructs with enhanced bone-forming capability. The Col/Hap apatite composites were prepared by immersing Col sponges alternately in calcium and phosphate ion solutions five times, for 20 and 60 min, respectively. Then, the sponges were heated to 56 °C for 48 h. Scanning electron microscopy/energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction analyses showed that the Col/Hap composites contained poorly crystalline Hap precipitates on the Col matrix. Col/Hap composite granules were infiltrated by AG, freeze-dried, and immersed in b-FGF solution. The wet quaternary constructs were implanted in rat cranial bone defects for 8 weeks, followed by soft X-ray measurements and histological analysis. Animal studies have shown that the constructs moderately increase bone formation in cranial bone defects. We found that an alternate immersion time of 20 min led to the greatest bone formation (p < 0.05). Constructs placed inside defects slightly extend the preexisting bone from the defect edges and lead to the formation of small island-like bones inside the defect, followed by disappearance of the constructs. The combined use of Col, Hap, AG, and b-FGF might bring about novel bone-forming biomaterials.

Self-Prepared Hyaluronic Acid/Alkaline Gelatin Composite with Nano-Hydroxyapatite and Bone Morphogenetic Protein for Cranial Bone Formation

“…Specimens from each disk sample (BMP (−) constructs (n = 6) and BMP (+) constructs (n = 8)) were implanted in the calvarial bone defects ( Figure 15 ), whereas six holes were left empty (defect only) (n = 6). The defects were covered with self-prepared collagen membranes [ 56 ]. The flaps were repositioned and sutured using soft nylon (Softretch 4-0, GC, Tokyo, Japan).…”

“… ( a ) Drilling a hole in rat cranial bone with trephine bur, ( b ) insertion of disk specimen in the cranial defect, ( c ) covering the defect with a self-prepared collagen membrane. Note: the membrane assisted in stopping bleeding, wound healing, preventing infection, fall prevention of the inserted construct, and bone formation, and disappeared within 8 weeks after insertion [ 56 ]. …”

Calcium Phosphate Loaded Biopolymer Composites—A Comprehensive Review on the Most Recent Progress and Promising Trends

“…The examined HAp-collagen scaffolds exhibited very high porosity with interconnected and irregular porous networks, and contained low-crystalline HAp nanoparticles which were homogeneously incorporated into collagen fibers [63]. In vitro studies also proved that these scaffolds were biocompatible and ensured excellent cell viability in terms of cell adhesion and proliferation [52]. Another observation was that the increase in HAp concentration within the composite affected neither cell growth nor bone generation [52,58].…”

“…It is well known that bone is a mixture of apatite and collagen. To mimic the structure of the bone, numerous studies have been conducted trying to reveal the best apatite-collagen composite constructions and preparation methods [52]. However, the characteristics of the apatite-collagen composites developed so far cannot come close to the properties of natural bone.…”

3D Printing and Performance Study of Porous Artificial Bone Based on HA-ZrO2-PVA Composites

“…Stefania De Luca et al studied the coating of three-dimensional porous glass-derived scaffolds with hyaluronic acid (HA)-fatty acids, which are expected to combine the bone-bonding properties of the glass with the wound-healing promotion carried out by the polymeric conjugates [ 11 ]. Miki Hoshi studied collagen (Col)/hydroxyapatite (Hap)/acidic gelatin (AG)/basic fibroblast growth factor (b-FGF) constructs with enhanced bone-forming capability, which might bring about novel bone-forming biomaterials [ 12 ]. In addition, compared with other calcium phosphate-based materials, the artificial bone prepared by hydroxyapatite will face multi-energy UV and X-ray detection in the later stage, which may cause the aging of artificial bone [ 13 , 14 ].…”