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The development of patient‐specific bone scaffolds that can expedite bone regeneration has been gaining increased attention, especially for critical‐sized bone defects or fractures. Precise adaptation of the scaffold to the region of implantation and reduced surgery times are also crucial at clinical scales. To this end, bioactive fluorcanasite glass‐ceramic microparticulates were incorporated within a biocompatible photocurable resin matrix following which the biocomposite resin precursor was 3D‐printed with digital light processing method to develop the bone scaffold. The printing parameters were optimized based on spot curing investigation, particle size data, and UV–visible spectrophotometry. In vitro cell culture with MG‐63 osteosarcoma cell lines and pH study within simulated body fluid demonstrated a noncytotoxic response of the scaffold samples. Further, the in vivo bone regeneration ability of the 3D‐printed biocomposite bone scaffolds was investigated by implantation of the scaffold samples in the rabbit femur bone defect model. Enhanced angiogenesis, osteoblastic, and osteoclastic activities were observed at the bone‐scaffold interface, while examining through fluorochrome labelling, histology, radiography, field emission scanning electron microscopy, and x‐ray microcomputed tomography. Overall, the results demonstrated that the 3D‐printed biocomposite bone scaffolds have promising potential for bone loss rehabilitation. [ABSTRACT FROM AUTHOR]

Natural bone healing is often inadequate to treat fractures with critical size bone defects and massive bone loss. Immediate surgical interventions through bone grafts have been found to be essential on such occasions. Naturally harvested bone grafts, although are the preferred choice of the surgeons; they suffer from serious clinical limitations, including disease transmission, donor site morbidity, limited supply of graft etc. Synthetic bone grafts, on the other hand, offer a more clinically appealing approach to decode the pathways of bone repair through use of tissue engineered biomaterials. This article critically retrospects the translational research on various engineered biomaterials towards bringing transformative changes in orthopaedic healthcare. The first section of the article discusses about composition and ultrastructure of bone along with the global perspectives on statistical escalation of bone fracture surgeries requiring use of bone grafts. The next section reviews the types, benefits and challenges of various natural and synthetic bone grafts. An overview of clinically relevant biomaterials from traditionally used metallic, bioceramic, and biopolymeric biomaterials to new generation composites have been summarised. Finally, this narrative review concludes with the discussion on the emerging trends and future perspectives of the promising bone grafts. [ABSTRACT FROM AUTHOR]

Magnesium (Mg) alloy‐based porous bio‐nanocomposite bone scaffolds were developed by powder metallurgy route. Selective alloying elements such as calcium (Ca), zinc (Zn) and strontium (Sr) were incorporated to tune the mechanical integrity while, bioactive fluorcanasite nano‐particulates were introduced within the alloy system to enhance the bone tissue regeneration. Green compacts containing carbamide were fabricated and sintered using two‐stage heat treatment process to achieve the targeted porosities. The microstructure of these fabricated magnesium alloy‐based bio‐nanocomposites was examined by Field emission scanning electron microscope (FE‐SEM) and x‐ray micro computed tomography (x‐ray μCT), which revealed gradient porosities and distribution of alloying elements. X‐ray diffraction (XRD) studies confirmed the presence of major crystalline phases in the fabricated samples and the evolution of the various combinations of intermetallic phases of Ca, Mg, Zn and Sr which were anticipated to enhance the mechanical properties. Further, XRD studies revealed the presence of apatite phase for the immersed samples, a conducive environment for bone regeneration. The fabricated samples were evaluated for their mechanical performance against uniaxial compression load. The tunability of compressive strengths and modulus values could be established with variation in porosities of fabricated samples. The retained compressive strength and Young's modulus of the samples following immersion in phosphate buffered saline (PBS) solution was found to be in line with that of natural human cancellous bone, thereby establishing the potential of the fabricated magnesium‐alloy‐based nanocomposite as a promising scaffold candidate for bone tissue engineering. [ABSTRACT FROM AUTHOR]

There has been significant interest in the recent past to develop injectable hydrogel scaffolds that follow minimally invasive implantation procedures towards efficient healing and regeneration of defective bone tissues. Such scaffolds offer several advantages, as they can be injected into the irregularly shaped defect and can act as a low‐density aqueous reservoir, incorporating necessary components for bone tissue repair and augmentation. Considering that bone is a biocomposite of natural biopolymer and bioapatite nanofiller, there has been a growing trend to develop nanocomposite scaffolds by combining biopolymers and inorganic nanofillers to biomimic the hierarchical nanostructure and composition of natural bone. Furthermore, the nanocomposite scaffolds can be tailored to have patient‐specific bone properties, which can lead to better biological responses. The present article begins with the introduction, followed by an overview of polymer matrices, property requirements, and crosslinking techniques employed for injectable hydrogels. Various strategies to develop injectable composites, with emphasis on nanocomposite hydrogels incorporating bioinert and bioactive nanofillers have been discussed. The fundamental challenges related to the development of injectable hydrogel nanocomposite scaffolds and the research efforts directed towards solving these problems have also been reviewed. Finally, future trends and conclusions on new generation injectable hydrogel nanocomposite bone scaffolds have been discussed in this article. [ABSTRACT FROM AUTHOR]

Tiles are generally manufactured using ceramic materials or concrete. An attempt has been made here to manufacture tiles using thermoset polymer epoxy resin as matrix and waste wheat straw residue as filler. Wheat straw residual filler was efficiently incorporated within epoxy resin matrix to fabricate a range of biocomposite tiles. Two different loading levels of filler were subjected to either alkali (NaOH) treatment or a combination of silane and alkali treatment. These biocomposite tiles were investigated for microstructural changes and various mechanical, physical and thermal properties. Fourier transform infrared (FT-IR) spectroscopy studies indicated strong interactions of the functional groups of epoxy resin and wheat straw filler. Fractured biocomposite samples observed under field emission scanning electron microscopy (FE-SEM) further suggested better bonding between filler and matrix. Thermogravimetric analysis (TGA) showed enhanced thermal stability upon dual treatment. Substantial improvements in water resistance, flexural strength and flexural modulus of biocomposite samples also could be achieved upon dual treatment. [ABSTRACT FROM AUTHOR]

This study reports development of engineered fluorcanasite frankemenite-fluorapatite glass-ceramic materials for potential bone scaffold applications. A systematic approach was undertaken to selectively tune the glass compositions and process parameters towards developing bone mimicking crystalline microstructure and enhancement of bioactive response. Differential thermal analysis was performed to design a controlled two stage heat treatment profile to convert the synthesized glass compositions into glass-ceramics. X-ray diffraction studies confirmed the presence of fluorcanasite, frankamenite and fluorapatite as the predominant phases, where fluorapatite is anticipated to induce enhanced bioactivity. Scanning electron microscopy of the fractured glass-ceramics revealed interpenetrating lath like microstructure, responsible for mechanical interlocking of crystalline phases. Systematic pH study of the glass-ceramic candidates carried out in simulated body fluid (SBF) recorded initial increase followed by stable pH values, confirming bioactivity and minimal leaching. The results from our study therefore, establishes the promising potential of the novel glass-ceramic biomaterials. [ABSTRACT FROM AUTHOR]

We report development of poly(vinyl alcohol) (PVA)‐based novel injectable hydrogel nanocomposite scaffolds. Nanocellulose (NC), synthesized from agricultural biomass, was used as reinforcement within PVA matrix. The hydrogels were formed using physical crosslinking process involving multiple freeze–thaw cycles. A range of bio‐nanocomposite hydrogels were prepared with varying concentrations of NC. With increasing loading of NC, crystallinity was found to be increased, which could be attributed to nucleating effect and crystalline nature of nanofibrillar cellulose. Investigation of microstructural surface topology indicated reduced surface perturbations upon incorporation of NC. Fourier transform infrared spectroscopy studies further indicated presence of characteristic functional groups and possible interactions between PVA and NC. Enhanced structural integrity and dynamic stability of the bio‐nanocomposite hydrogels were also confirmed by carrying out rheological investigations at different frequency, amplitude, temperature, and time sweeps. Further, the bio‐nanocomposite hydrogels demonstrated excellent injectability and self‐standing behavior, establishing the promising potential as injectable scaffolds. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48789. [ABSTRACT FROM AUTHOR]

A modified microbial polysaccharide based biopolymer has been investigated as a potential candidate towards development of sustainable biomaterials and bioplastics. An in-depth study was carried out to biosynthesize, characterize and assess any possible mutagenic potential and ecotoxicity of the microbial polysaccharide biopolymer. Microstructural investigations using confocal microscopy, Fourier transform (FT)-Raman depth profile mapping and scanning electron microscopy (SEM) of the biosynthetically modified polysaccharide revealed internal structural perturbations, as well as occlusion of granular pores by extraneous materials. The Raman 3D mapping depth profile along with time-of-flight (MALDI-TOF) mass spectrometry also indicated important structural and surface modifications, which could be correlated to the production of microbial exopolysaccharides and secondary metabolites. The study then looked into any possible genetic mutation and ecological risks associated with the biosynthetically modified polysaccharide through the investigation of genotoxicity and ecotoxicity. The genotoxicity study was carried out through bacterial reverse gene mutation (Ames) test by using two different strains (TA98 and TA100) of bacteria. The results did not indicate any mutagenic effect against either of the strains used for the biopolymer samples and was found to be genotoxically safe. Ecotoxicity tests, carried out using bioluminescent bacteria Vibrio fisheri further indicated no ecotoxicity within the given experimental conditions. The study measured the half maximal effective concentration (EC50) to cause a 50% decrease in the light output of the bacteria, a measure of ecotoxicological response of the biopolymer. Overall, results from this study indicated that the novel biopolymer was genotoxically and ecotoxically safe, which offers immense potential for future use of this biopolymer. [ABSTRACT FROM AUTHOR]

Epoxy resin matrix based on diglycidyl ether of bisphenol A (DGEBA) was modified with addition of epoxidized soybean oil (ESBO). Structural jute composites prepared with ESBO modified DGEBA resin showed a decrease in tensile strengths, owing to reduced cross linking density. Percentage elongation of the samples increased with addition of ESBO. An optimized composition was identified, at which the composite showed increase in tensile strength, modulus and elongation. Interestingly, impact strengths increased initially with incorporation of ESBO, but with further increase in ESBO, impact strengths decreased. Structural Jute composites were also prepared by incorporating polyvinyl (chloride) (PVC) plastisol into the modified matrix which showed an increase in both tensile and impact strengths. Fourier transform infrared spectroscopy (FT-IR) analysis indicated the curing state of the composites. The spectrum peaks became increasingly stronger in the OH band with increasing ESBO quantities. This could be attributed to the hydrophilic nature of ESBO, a result that was well supported by the moisture absorption test. Although, water uptake capacity of ESBO/DGEBA modified matrix composites recorded increasing trend with increased ESBO content, with inclusion of plastisol, the water uptake values dropped. Composite with DGEBA/ESBO/plastisol modified matrix actually recorded water uptake capacity comparable to composite with neat DGEBA, possibly owing to improved interfacial adhesion and hydrophobic nature of PVC plastisol. POLYM. COMPOS., 37:391-397, 2016. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Natural bone healing is often inadequate to treat fractures with critical size bone defects and massive bone loss. Immediate surgical interventions through bone grafts have been found to be essential on such occasions. Naturally harvested bone grafts, although are the preferred choice of the surgeons; they suffer from serious clinical limitations, including disease transmission, donor site morbidity, limited supply of graft etc. Synthetic bone grafts, on the other hand, offer a more clinically appealing approach to decode the pathways of bone repair through use of tissue engineered biomaterials. This article critically retrospects the translational research on various engineered biomaterials towards bringing transformative changes in orthopaedic healthcare. The first section of the article discusses about composition and ultrastructure of bone along with the global perspectives on statistical escalation of bone fracture surgeries requiring use of bone grafts. The next section reviews the types, benefits and challenges of various natural and synthetic bone grafts. An overview of clinically relevant biomaterials from traditionally used metallic, bioceramic, and biopolymeric biomaterials to new generation composites have been summarised. Finally, this narrative review concludes with the discussion on the emerging trends and future perspectives of the promising bone grafts.