Binary polymer systems for biomedical applications

Binary polymer systems provide significant advantages in the preparation of materials used in biomedical applications. To highlight the importance and need of binary polymer systems in biomedical applications; utilisations of nano-carrier and fibre are discussed in detail in terms of their use as biomaterial, and their potential for further development with focus on dual and sequential drug delivery applications. On the other hand, in fibre technology, creation of binary polymer systems have been investigated using spinning processes such as electrospinning and even more recently innovated pressurised gyration. How these methods can be used to promote the mass production of binary polymer systems with various morphologies and characteristics are elucidated. The effects of different polymer materials, including solvents, mechanical properties, and the rate of degradation of polymers, are discussed. Current polymer blending systems and manufacturing processes are analysed, and technologies for biomaterials are carefully considered with up to date details

Iron-based magnetic nanosystems for diagnostic imaging and drug delivery : towards transformative biomedical applications

The advancement of biomedicine in a socioeconomically sustainable manner while achieving efficient patient-care is imperative to the health and well-being of society. Magnetic systems consisting of iron based nanosized components have gained prominence among researchers in a multitude of biomedical applications. This review focuses on recent trends in the areas of diagnostic imaging and drug delivery that have benefited from iron-incorporated nanosystems, especially in cancer treatment, diagnosis and wound care applications. Discussion on imaging will emphasise on developments in MRI technology and hyperthermia based diagnosis, while advanced material synthesis and targeted, triggered transport will be the focus for drug delivery. Insights onto the challenges in transforming these technologies into day-to-day applications will also be explored with perceptions onto potential for patient-centred healthcare

Using Pressurised Spinning to Fabricate Multifunctional and Binary Polymeric Fibres for Biomedical Applications

Healthcare applications have long made use of biomaterials, which are continually evolving. Tissue engineering, wound healing, and biomedical engineering have each been revolutionised by biomaterials. Polymeric properties and manufacturing procedures have been researched, fabricated, and characterised for their performance. The first part of this work has addressed the demand for suitable polymer-based nanodelivery system with antimicrobial properties to overcome challenges in wound care. Polyethylene oxide (PEO) has attracted considerable interest in biomedical applications due to its non-toxicity, hydrophilicity and biocompatability. Pressurised gyration (PG) was utilised as a technique to fabricate water-soluble PEO nanofibres incorporated with two different types of antimicrobial peptides (AMPs), M2 and AMP2, using distilled water. The effect of varying applied PG working pressure, along with the impact on the fibre diameter and morphology was reported. At 0.3 MPa, nanofibres ranging in the diameters of 200-250 nm were successfully produced, and significant bacterial viability against Staphylococcus epidermidis was achieved utilising AMP2 peptides at 105 µg/ mL. The subsequent section of this study focused on a novel fabrication of polymer composite fibres using polycaprolactone (PCL) incorporated with montmorillonite nanoclay (MMT-Clay) and hydroxyapatite nanoclay (HAP MMT-Clay) for bone tissue regeneration. Scaffolds are physical substrates for cell attachment, proliferation, and differentiation, ultimately leading to the regeneration of tissues. As a biomaterial for scaffold production, PCL provides various advantages, including tuneable biodegradation and relatively high mechanical toughness. Using the PG process, PCL HAP-Clay and PCL HAP MMT-Clay fibres were successfully manufactured at 2-5 w/w %. The 3D nanoclay PCL fibre scaffolds were able to enhance bone growth, cell viability, and proliferation. It was demonstrated that the polymer fibre scaffolds were biocompatible, and the mesenchymal stem cells (MSCs) and osteoblasts were able to thrive and differentiate on the fibre scaffolds. Ultimately, a significant increase in cell viability, osteogenic differentiation, extracellular matrix (ECM) formation, and collagen formation were observed with the PCL HAP MMT-Clay fibre scaffolds (5 w/w %) compared to the control PCL fibres. Further, the intracellular alkaline phosphatase (ALP) levels were increased with PCL HAP MMT-Clay fibre scaffolds, indicative of enhanced osteogenic differentiation of MSCs. Although singular polymeric fibres performed significantly as biomaterials, they were not without limitations. Binary polymer systems create an optimum combination of both polymer properties. Thus, PEO and PCL were combined in a blend system in the ratios 14:1-1:4 dissolved in chloroform and spun into fibres. The resulting polymer solutions were characterised for their rheology and surface tension properties. Scanning electron microscopy (SEM) was utilised to analyse the influence of increasing PEO ratio on the binary PCL:PEO polymer systems for their morphology and topography. It was observed that an increase in PEO ratio resulted in a decrease in the average fibre diameters, ranging at 3.4 ± 1.8 µm – 1.5 ± 0.4 µm. Binary fibres were subjected to swelling test, having been immersed in deionised water for 15-60 min, and the impact of PEO on swelling behaviour was evaluated using an optical microscopy. The comparison of solution properties, morphology, and swelling behaviour resulted in the establishment of an optimised binary polymer composition. As a model drug, caffeine (CAF) was incorporated into singular PCL and PEO polymer matrix, as well as optimised PCL:PEO polymers. Fourier transform infrared (FTIR) spectroscopy was performed on control fibres and PCL:PEO-CAF fibres. The presence of singular polymers in the binary polymer matrix was confirmed by FTIR, which also revealed CAF in the singular and binary fibres. In-vitro drug release studies was conducted for an incubation period of 96 h on the PCL-CAF, PEO-CAF, and PCL:PEO-CAF fibres and the release of CAF was analysed. During the 24-96 h incubation period, PEO fibres indicated a rapid release profile of 47-67 %, PCL fibres exhibited a delayed release of 39-55 %, while binary PCL:PEO fibres revealed an enhanced release profile of 44-58 %, attributed to the modified singular polymer properties. By overcoming the shortcomings of singular polymers, this research exhibited that the binary polymer system offers an intriguing strategy for modifying polymer properties. This is an innovative PG-based blend system that can be utilised to create scaffolds for heterogeneous tissue engineering, remarkable therapeutic release, and antimicrobial attributes