Synthesis and in vivo evaluation of a scaffold containing wollastonite/β-TCP for bone repair in a rabbit tibial defect model

Polycaprolactone Hybrid Scaffold Loaded With N,O-Carboxymethyl Chitosan/Aldehyde Hyaluronic Acid/Hydroxyapatite Hydrogel for Bone Regeneration

Hydrogels have emerged as potential materials for bone grafting, thanks to their biocompatibility, biodegradation, and flexibility in filling irregular bone defects. In this study, we fabricated a novel NAH hydrogel system, composed of N,O-carboxymethyl chitosan (NOCC), aldehyde hyaluronic acid (AHA), and hydroxyapatite (HAp). To improve the mechanical strength of the fabricated hydrogel, a porous polycaprolactone (PCL) matrix was synthesized and used as a three-dimensional (3D) support template for NAH hydrogel loading, forming a novel PCL/NAH hybrid scaffold. A mixture of monosodium glutamate (M) and sucrose (S) at varied weight ratios (5M:5S, 7M:3S, and 9M:1S) was used for the fabrication of 3D PCL matrices. The morphology, interconnectivity, and water resistance of the porous PCL scaffolds were investigated for optimal hydrogel loading efficiency. The results demonstrated that PCL scaffolds with porogen ratios of 7M:3S and 9M:1S possessed better interconnectivity than 5M:5S ratio. The compressive strength of the PCL/NAH hybrid scaffolds with 9M:1S (561.6 ± 6.1 kPa) and 7M:3S (623.8 ± 6.8 kPa) ratios are similar to cancellous bone and all hybrid scaffolds were biocompatible. Rabbit models with tibial defects were implanted with the PCL/NAH scaffolds to assess the wound healing capability. The results suggest that the PCL/NAH hybrid scaffolds, specifically those with porogen ratio of 7M:3S, exhibit promising bone healing effects.

A Review on the Role of Wollastonite Biomaterial in Bone Tissue Engineering

Millions of people around the world have bone-tissue defects. Autologous and allogeneic bone grafting are frequent therapeutic techniques; however, none has produced the best therapeutic results. This has inspired researchers to investigate novel bone-regeneration technologies. In recent years, the development of bone tissue engineering (BTE) scaffolds has been at the forefront of this discipline. Due to their limitless supply and lack of disease transmission, engineered bone tissue has been advanced for the repair and reconstruction of bone deformities. Bone tissue is a highly vascularized, dynamic tissue that constantly remodels during an individual's lifetime. Bone tissue engineering is aimed at stimulating the creation of new, functional bone by combining biomaterials, cells, and factor treatment synergistically. This article provides a review of wollastonite's biomaterial application in bone tissue engineering. This work includes an explanation of wollastonite minerals including mining, raw materials for the synthesis of artificial wollastonite with various methods, its biocompatibility, and biomedical applications. Future perspectives are also addressed, along with topics like bone tissue engineering, the qualities optimal bone scaffolds must have, and the way a scaffold is designed can have a big impact on how the body reacts.

Hybrid Microwave Solid-Phase Synthesis of Wollastonite Based on Natural Renewable Raw Materials

Abstract

A method was tested to perform the solid-phase synthesis of ceramic wollastonite under hybrid microwave heating using such natural renewable raw materials as sea shells as a source of CaCO3 with the addition of commercial SiO2 powder. The XRD, SEM, TGA, and EDS methods were used to explore the effect of the mechanical homogenization time and the conditions for the chemical interaction of raw materials, provided that the required phase composition is reached. It was studied how temperature (800–1150°C) and time (15–60 min) of sintering affect the composition and structure of the ceramic wollastonite samples, including those in the presence of the strengthening additive sodium tetraborate. The formation of an apatite (Ca10(PO4)6(OH)2) layer on the surface of the obtained samples under conditions of their contact with artificial human blood plasma was assessed to confirm the biocompatible properties of these materials. The proposed method of synthesis is promising for obtaining a chemically pure valuable biomaterial in the form of synthetic wollastonite with the possibility of rational use of biogenic raw materials.

A review on bioceramics scaffolds for bone defect in different types of animal models: HA and β -TCP

Increased life expectancy has led to an increase in the use of bone substitutes in numerous nations, with over two million bone-grafting surgeries performed worldwide each year. A bone defect can be caused by trauma, infections, and tissue resections which can self-heal due to the osteoconductive nature of the native extracellular matrix components. However, natural self-healing is time-consuming, and new bone regeneration is slow, especially for large bone defects. It also remains a clinical challenge for surgeons to have a suitable bone substitute. To date, there are numerous potential treatments for bone grafting, including gold-standard autografts, allograft implantation, xenografts, or bone graft substitutes. Tricalcium phosphate (TCP) and hydroxyapatite (HA) are the most extensively used and studied bone substitutes due to their similar chemical composition to bone. The scaffolds should be testedin vivoandin vitrousing suitable animal models to ensure that the biomaterials work effectively as implants. Hence, this article aims to familiarize readers with the most frequently used animal models for biomaterials testing and highlight the available literature for in vivo studies using small and large animal models. This review summarizes the bio ceramic materials, particularly HA and β-TCP scaffolds, for bone defects in small and large animal models. Besides, the design considerations for the pre-clinical animal model selection for bone defect implants are emphasized and presented.

Comparative review of piezoelectric biomaterials approach for bone tissue engineering

Bone as a minerals' reservoir and rigid tissue of the body generating red and white blood cells supports various organs. Although the self-regeneration property of bone, it cannot regenerate spontaneously in severe damages and still remains as a challenging issue. Tissue engineering offers several techniques for regenerating damaged bones, where various biomaterials are examined to fabricate scaffolds for bone repair. Piezoelectric characteristic plays a crucial role in repairing and regenerating damaged bone by mimicking the bone niche behavior. Piezoelectric biomaterials show significant potential for bone tissue engineering. Herein we try to have a comparative review on piezoelectric and non-piezoelectric biomaterials used in bone tissue engineering, classified them, and discussed their effects on implanted cells and manufacturing techniques. Especially, Polyvinylidene fluoride (PVDF) and its composites are the most practically used piezoelectric biomaterials for bone regeneration. PVDF and its composites have been summarized and discussed to repair damaged bone tissues.

Tissue-engineered bones with adipose-derived stem cells - composite polymer for repair of bone defects

Background: Development of alternative bone tissue graft materials based on tissue engineering technology has gradually become a research focus. Engineered bone composed of biodegradable, biosafe and bioactive materials is attractive, but also challenging. Materials & methods: An adipose-derived stem cell/poly(L-glutamic acid)/chitosan composite scaffold was further developed for construction of biodegradable and bone-promoting tissue-engineered bone. A series of composite scaffold materials with different physical properties such as structure, pore size, porosity and pore diameter was developed. Results: The composite scaffold showed good biodegradability and water absorption, and exhibited an excellent ability to promote bone differentiation. Conclusion: This type of biodegradable scaffold is expected to be applied to the field of bone repair or bone tissue engineering.

Bone regeneration using Wollastonite/β-TCP scaffolds implants in critical bone defect in rat calvaria

In order to provide favorable conditions for bone regeneration, a lot of biomaterials have been developed and evaluated, worldwide. Composite biomaterials have gained notoriety, as they combine desirable properties of each isolated material. Thus, in this research, bone repair capacity of three developed formulations of ceramic scaffolds were evaluated histomorphometrically, after implantation. Scaffolds were based on wollastonite (W) andβ-tricalcium phosphate (β-TCP) composites in three different ratios (wt.%). ThirtyWistarrats were randomly assigned to three experimental groups: W-20 (20 W/80β-TCP wt.%), W-60 (60 W/40β-TCP wt.%), and W-80 (80 W/20β-TCP wt.%), evaluated by optical microscopy at biological tests after 15 and 45 days of implantation. Throughout the study, the histological results evidenced that the scaffolds remained at the implantation site, were biocompatible and presented osteogenic potential. The percentage of neoformed mineralized tissue was more evident in the W-20 group (51%), at 45 days. The composite of the W-80 group showed more evident biodegradation than the biomaterials of the W-20 and W-60 groups. Thus, it is concluded that the scaffold containing 20 W/80β-TCP (wt.%) promoted more evident bone formation, but all composites evaluated in this study showed notorious bioactivity and promising characteristics for clinical application.

Development of highly porous calcium phosphate bone cements applying nonionic surface active agents

A novel way of obtaining highly porous cements is foaming them with the use of nonionic surface active agents (surfactants). In this study, foamed calcium phosphate cements (fCPCs) intended for in situ use were fabricated by a surfactant-assisted foaming process. Three different surface active agents, Tween 20, Tween 80 and Tetronic 90R4, were used. The amount of surfactant, based on its critical micelle concentration and cytotoxicity as well as foaming method, was determined. It has been established that in order to avoid cytotoxic effects the concentration of all applied surfactants in the cement liquid phases should not exceed 1.25 g L⁻¹. It was found that Tetronic 90R4 had the lowest cytotoxicity whereas Tween 20 had the highest. The influence of the type of surfactant used in the fabrication process of bioactive macroporous cement on the physicochemical and biological properties of fCPCs was studied. The obtained materials reached higher than 50 vol% open porosity and possessed compressive strength which corresponds to the values for cancellous bone. The highest porosity and compressive strength was found for the material with the addition of Tween 80. In vitro investigations proved the chemical stability and high bioactive potential of the examined materials.

A novel way of obtaining highly porous cements is foaming them with the use of nonionic surface active agents (surfactants).

Morphological Characteristics of the Osteoplastic Potential of Synthetic CaSiO3/HAp Powder Biocomposite

The study describes the influence of synthetic CaSiO₃/HAp powder biocomposite on the process of regeneration in osseous tissue in the alveolar ridges in terms of the morphological characteristics of the osteoplastic potential. The authors investigated the osteoinduction and osteoconduction “in vivo” processes during bone tissue regeneration in the mandible defect area of an experimental animal (rabbit). The possibility of angiogenesis in the graft as an adaptation factor was studied in the process of bone tissue regeneration. The results of the histological study that included the qualitative parameters of bone tissue regeneration, the morphometric parameters (microarchitectonics) of the bone, the parameters of osteosynthesis (thickness of the osteoid plates), and resorption (volume density of the eroded surface) were presented. The results allowed the authors to characterize the possibility of the practical adaptation for synthetic powder biocomposite as an osteoplastic graft for the rehabilitation of osseous defects in dentistry.

Vascular Supply and Bone Marrow Concentrate for the Improvement of Allograft in Bone Defects: A Comparative In Vivo Study

BACKGROUND

Surgical repair of critical-sized bone defects still remains a big challenge in orthopedic surgery. Biological enhancement, such as growth factors or cells, can stimulate a better outcome in bone regeneration driven by well-established treatments such as allogenic bone graft. However, despite the surgical options available, correct healing can be slowed down or compromised by insufficient vascular supply to the injured site.

MATERIALS AND METHODS

In this pilot study, critical size bone defects in rabbit radius were treated with allograft bone, in combination with vascular bundle and autologous bone marrow concentrate seeded onto a commercial collagen scaffold. Microtomographical, histological and immunohistochemical assessments were performed to evaluate allograft integration and bone regeneration.

RESULTS

Results showed that the surgical deviation of vascular bundle in the bone graft, regardless from the addition of bone marrow concentrate, promote the onset of healing process at short experimental times (8 wk) in comparison with the other groups, enhancing graft integration.

CONCLUSION

The surgical procedure tested stimulates bone healing at early times, preserving native bone architecture, and can be easily combined with biological adjuvant.