Mechanical properties of green composites with polycaprolactone and wheat gluten

Natural Fiber-Reinforced Polycaprolactone Green and Hybrid Biocomposites for Various Advanced Applications

Recent developments within the topic of biomaterials has taken hold of researchers due to the mounting concern of current environmental pollution as well as scarcity resources. Amongst all compatible biomaterials, polycaprolactone (PCL) is deemed to be a great potential biomaterial, especially to the tissue engineering sector, due to its advantages, including its biocompatibility and low bioactivity exhibition. The commercialization of PCL is deemed as infant technology despite of all its advantages. This contributed to the disadvantages of PCL, including expensive, toxic, and complex. Therefore, the shift towards the utilization of PCL as an alternative biomaterial in the development of biocomposites has been exponentially increased in recent years. PCL-based biocomposites are unique and versatile technology equipped with several importance features. In addition, the understanding on the properties of PCL and its blend is vital as it is influenced by the application of biocomposites. The superior characteristics of PCL-based green and hybrid biocomposites has expanded their applications, such as in the biomedical field, as well as in tissue engineering and medical implants. Thus, this review is aimed to critically discuss the characteristics of PCL-based biocomposites, which cover each mechanical and thermal properties and their importance towards several applications. The emergence of nanomaterials as reinforcement agent in PCL-based biocomposites was also a tackled issue within this review. On the whole, recent developments of PCL as a potential biomaterial in recent applications is reviewed.

Preparation and characterization of polycaprolactone/chitosan-g-polycaprolactone/hydroxyapatite electrospun nanocomposite scaffolds for bone tissue engineering

Chitosan (CS) and poly (ε-caprolactone) (PCL) are two most usable polymers in biomedical applications. In this study, chitosan has been modified and incorporated with poly (ε-caprolactone) to fabricate bone tissue engineering scaffold. Moreover, hydroxyapatite nanoparticles were added to enhance bioactivity and mechanical properties of scaffold. Bulk and fibrous comparative results showed significant effect of fiber diameter and distribution on mechanical properties. Moreover, the incorporation of chitosan-g-poly (ε-caprolactone) (CS-g-PCL) significantly decreases fiber diameter of pure PCL scaffold. Furthermore, both CS-g-PCL and nHA enhance mineralization and degradation of the scaffold soaked in simulated body fluid (SBF) and phosphate buffered saline (PBS), respectively. In vitro cytocompatibility assays also confirmed high cell viability and proliferation on the samples. Taken together, the results suggest that the microfabricated nanocomposite scaffolds could be used in bone tissue engineering.

Biological and mechanical characterization of biodegradable carbonyl iron powder/polycaprolactone composite material fabricated using three-dimensional printing for cardiovascular stent application

Biological and mechanical properties of biodegradable polymeric composite materials are strongly influenced by the choice of appropriate reinforcement in the polymer matrix. Non-compatibility of material in the vascular system could obstruct the way of the biological fluids. The concept of development of polymeric composite material for vascular implants is to provide enough support to the vessel and to restore the vessel in the natural state after degradation. In this research, the polycaprolactone composite materials (carbonyl iron powder/polycaprolactone) were developed by reinforcement of the 0%–2% of carbonyl iron powder using the solvent cast three-dimensional printing technique. The physicochemical properties of developed composites were characterized in conjunction with mechanical and biological properties. The mechanical characterizations were assessed by uniaxial tensile testing as well as flexibility testing. The results of mechanical testing assured that carbonyl iron powder/polycaprolactone composites have shown desirable properties for vascular implants. Besides the mechanical characterization, in vitro biological investigations of carbonyl iron powder/polycaprolactone were done for analyzing blood compatibility and cytocompatibility. The results revealed that the materials developed were biocompatible, less hemolytic, and having non-thrombogenic properties indicating the promising applications in the field of cardiovascular applications.

The effect of pore size within fibrous scaffolds fabricated using melt electrowriting on human bone marrow stem cell osteogenesis

Limitations associated with current bone grafting materials has necessitated the development of synthetic scaffolds that mimic the native tissue for bone repair. Scaffold parameters such as pore size, pore interconnectivity, fibre diameter, and fibre stiffness are crucial parameters of fibrous bone tissue engineering (BTE) scaffolds required to replicate the native environment. Optimum values vary with material, fabrication method and cell type. Melt electrowriting (MEW) provides precise control over extracellular matrix (ECM)-like fibrous scaffold architecture. The goal of this study was to fabricate and characterise poly-ε-caprolactone (PCL) fibrous scaffolds with 100, 200, and 300 μm pore sizes using MEW and determine the influence of pore size on human bone marrow stem cell (hMSC) adhesion, morphology, proliferation, mechanosignalling and osteogenesis. Each scaffold was fabricated with a fibre diameter of 4.01 ± 0.06 μm. The findings from this study highlight the enhanced osteogenic effects of controlled micro-scale fibre deposition using MEW, where the benefits of 100 μm square pores in comparison with larger pore sizes are illustrated, a pore size traditionally reported as a lower limit for osteogenesis. This suggests a lower pore size is optimal when hMSCs are seeded in a 3D ECM-like fibrous structure, with the 100 μm pore size optimal as it demonstrates the highest global stiffness, local fibre stiffness, highest seeding efficiency, maintains a spread cellular morphology, and significantly enhances hMSC collagen and mineral deposition. Similarly, this platform represents an effective in vitro model for the study of hMSC behaviour to determine the significant osteogenic benefits of controlling ECM-like fibrous BTE scaffold pore size using MEW.

Effects of Bamboo Shoot Dietary Fiber on Mechanical Properties, Moisture Distribution, and Microstructure of Frozen Dough

In this paper, the effects of Bamboo shoot dietary fiber (BSDF) on the mechanical properties, moisture distribution, and microstructure of frozen dough were investigated. The state and distribution of water in frozen dough was determined by differential scanning calorimetry (DSC) and low-field nuclear magnetic resonance (LNMR) spectroscopy. The microstructure of frozen dough was studied. The structure of the gluten protein network found in wheat flour dough was studied by scanning electron microscopy (SEM). The result showed that the BSDF could significantly improve the viscoelasticity and extensibility of frozen dough after thawing in a dose-dependent manner. It was significantly improved with the increase in the addition amount of BSDF (P<0.05). DSC analysis showed that the freezable water content and thermal stability of frozen dough were increased after the addition of BSDF. LNMR analysis showed that the appropriate (<0.1%) addition amount of BSDF could significantly (P<0.05) decline the contents of bound water. Meanwhile, the loose bound water and free water were raised significantly (P<0.05) after the addition of BSDF. Moreover, the addition of BSDF induces arrangement of starch granule and gluten network in frozen dough. BSDF can be used as a novel quality improver of frozen dough.