Bone tissue engineering is considered as one of the most innovative biomedical technology in the reconstruction and repair of injured tissues linked with tumor resections, osteoporosis, cancer, trauma, or/and infections/inflammation[1, 2]. For this purpose, there is an emergency demand for developing bioceramic material that can assist the regeneration of tissues.3
In this point of view, different types of bioceramic materials are being developed and utilized for tissue engineering applications. Among these materials, HAp has attracted considerable attention, and also established to be a prospective bone substitute bioceramic materials [4, 5] due to the numerous essential advantages such as high bioactivity, excellent biocompatibility, osteoconductivity and non toxicity, etc. In addition to this, HAp is an essential candidate because it can form a direct bond with natural bone owing to its resemblance with the mineral fraction of natural bone in chemical and crystallographic structure with living tissues .
Different preparation method such as co-precipitation, hydrothermal, sol-gel, ultrasonication and heat treatment has been tailored for HAp synthesis [8–11]. Nowadays, young scientists have mostly focused on the preparation of pure HAp from the biowaste material. Because, then the readily available HAp is very costly owing to the usage of analytical reagents in the synthesis of HAp. As a result, researchers across the world are progressively searching an alternative means toward cost reduction by utilizing some kinds of natural waste materials using the concepts of “waste to wealth” . This great idea gives a novelty to generate a new and safe valuable product from the biowaste material. In addition, these materials can be converted into more precious things which maintains environment safe .
Recently, HAp has been synthesized from the biogenically waste material such as fish bone, bovine bone, egg shells and sea shells, etc.[14–17] Due to some resemblance in chemical contents and commercial HAp, it has been motivated possibility to produce HAp material from fish bones. Therefore, fish bone (biowaste) material was used for the synthesis of HAp and this is one of the best ways to minimize the cost [15, 16]. Hence, fish bone has been used as a raw biomaterial for the synthesis of novel HAp. Generally, it is imperative to note down that owing to the growing use of fish worldwide, considerable quantity of fish waste is being formed every year . Universally about 970–2700 billion tons of fish are caught, in which 450–1000 billion are utilized for human consumptions and the remaining is used for fish oil extraction. Hence, utilization of fish bone material can significantly support sustainable environmental development and reduces the environmental issues.
In particular, fish bones are mainly composed of water, collagen, and connective tissue proteins and the remaining 41–84% of other proteins [4, 18]. There are various series of calcium phosphate salts, which are mainly present in fish bone owing to their excellent biological response in physiological environment [12, 13]. Hence, HAp sample was extracted by calcinating the fish bones at various temperatures. Extraction of HAp from fish bone is low cost and biologically safe, since it is easy to obtain . All of these advantages make the as-synthesized HAp from fish bone material more attractive for bone tissue engineering applications . The HAp exhibits low mechanical strength and rigidity which may not be appropriate for tissue engineering applications . In this biomedical point of view, material researchers are focusing on the incorporation of commercial reinforcing materials like carbon nano tubes, carbon nanofibre and some oxides, etc., for the enhancement of mechanical properties [22–24]. However, the cost of commercial reinforcing agents is extremely expensive which sometimes limits the research findings . Therefore, recent researchers are seeking alternative methods towards cost reduction of the reinforcing material [26, 27]. For this purpose, scientists mainly focus on the use of agro-wastes to achieve high expensive biomaterials in an environment friendly approach and sustainable way which can be utilized in tissue engineering applications . In the past few decades, some researchers are focusing on probing natural fibers as reinforcement material in pure HAp, such as hemp, bamboo fiber, jute and kenaf, which were mainly united with biomaterials, so as to find a novel variety of completely bioactive “green composite” .
Among various types of polysaccharides such as alginate, cellulose and chitosan possess several advantages like excellent biocompatibility, noncytotoxicity and biodegradability . Generally, cellulose is superior recognized as renewable, biodegradable, biocompatible, thermal stability, environmental friendly biomaterial and non-edible low cost source, representing one of the abundant natural polymer material on earth. Nowadays, cellulose nanofibre (CNF) derived from natural cellulosic sources, are being increasingly examined owing to their special properties [31, 32]. In addition, most CNF have attracted vital significance in tissue engineering applications due to their nanoscale dimensions, low density, high aspect ratio and mainly impressive biological, mechanical and thermal properties. All of these properties make HAp/CNF composite highly attractive for bone tissue engineering applications. Since there is no diverse bioceramic material obtainable to fulfill all the required needs in the biological field, development of biocomposites as a preferred method for biomedical applications has become mandatory . Hence, the incorporation of bone-bioceramic component of HAp into the CNF has revealed superior interaction and better mechanical properties . This HAp/CNF composite is used in biological process confirms poor antibacterial properties which cannot be appropriate for bone tissue engineering applications.
Curcumin (Cur) is a more active yellow material from Curcuma longa L., which is commonly employed as a flavoring agent and coloring in herbal medicine and food industry in Asian countries to cure the diarrhea, vomiting, headache etc. Generally, curcumin is very safe and healthy product to human and is extensively used for treating Alzheimer’s, cystic fibrosis and malarial diseases [35–38]. Based on these positive points, we have concluded that the curcumin could enhance the antibacterial property of the HAp/CNF composite, and thus, a novel biocompatible trinary HAp/CNF/Cur composite is achieved. A composite of HAp/CNF/Cur is expected to contribute a more positive arrangement of biological and mechanical properties and also it is a vital role in the area of biomaterial field. However, as far as we know, the HAp/CNF/Cur composite aimed has not been reported yet.
Thus, the present work aims to implement a green and natural benign procedure consisting of HAp/CNF/Cur composite to deliver enhanced thermal, biological and mechanical properties, so as to provide as a potential applicant for bone tissue engineering applications.