A careful selection of monomers for biomaterial syntheses is essential for determining and controlling the functionality and biocompatibility of the biomaterials to be produced. Synthetic polyester elastomers based on molecules that are endogenous to the human metabolism have been designed [1]. In earlier studies, several investigators have reported elastic polyesters based on citric acid, in particular polyoctanediol citrate (POC) [2], poly(alkenylene maleate citrate) [3], poly(xylitol-co-citrate) [4] and poly(mannitol citric dicarboxylate) [5]. Although a number of biodegradable elastomers have been developed, most of them require complex and expensive synthetic procedures, which translate into higher manufacturing costs and hinder the commercial and clinical implementation of their use in tissue engineering [6]. Also, as more stringent material requirement in tissue engineering is made, there is a continuous need for newer materials’ design and synthesis [7]. The objective of the present work is to design polyesters using citric acid, sebacic acid, itaconic acid and 1,12-dodecanediol. To synthesize the polyesters by melt condensation, thermal polyesterification technique without using catalysts or coreagents, making this method attractive for the synthesis of polyesters useful in medical applications. The chosen monomers are expected to provide the polyesters with physico-chemical properties that could be significantly impact the degradation and biocompatibility of the synthesized polyesters.
Materials and Methods
Results and Discussion
Synthesis and Characterization of the polyesters
The copolyesters were synthesized by melt condensation of monomers based on the schematic representation in Figures 1a and 1b.
The FT-IR spectra ...
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...en BG, Tse MY, Turner ND, Knight DK, Pang SC (2006) In vivo degradation behavior of photo-cross-linked star-poly(ε-caprolactone-co-D,L-lactide)elastomers. Biomacromolecules 7: 365-372.
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In this experiment we produced a Nylon-6,10 polymer from a reaction with a sebacoyl chloride (decanedioyl dichloride)/dichloromethane mixture and a mixture of water, 1,6-hexanediamine and sodium carbonate. The name ‘Nylon-6,10’ indicates that the diamine that it was made from has 6 carbons and the diacid it was made from has 10 carbons. The sodium carbonate was used in the preparation of Nylon-6,10 because it is a strong base that will lower the acidity of the solution and neutralize the hydrochloric acid that was produced as a by-product. The HCl was produced as a by-product instead of water because we used milder conditions by substituting decanedioyl dichloride for decanedioic acid. The decanedioyl dichloride is a better alternative because it is more reactive towards the
Naturally derived cross-linking reagents are considered superior to chemical cross-linking demonstrating a low toxicity level after implantation [9]. Genipin (GIP), an aglycone of geniposide obtained from Gardenia jasminoides Ellis Plant, was first discovered by Huang et al. in 1998 [29]. GIP is found to be 10,000 times less toxic than GA. GIP-fixed tissues, usually show resistance against enzymatic degradation as compared to GA resulting in the development of biocompatible cross-linked products [30]. In a recent study, Wang et al. reported that GIP alleviated the xenogeneic host response of decellularized porcine liver scaffolds by reducing the proliferation of lymphocytes and their subsets, accompanied by a decreased release of both Th1 and Th2 cytokines. It was reported that cross-linking using GIP promotes the beneficial tissue repair through enhancing angiogenesis and cell migration
Up to present date there are many polymer hosts [1] have been discovered and some examples are
Regenerative medicine targets the conservation and development of organ function. The modification of tissues is obtained by linking living cells with materials that work as scaffolds to support cell generation. Nanotechnology is the means that feeds the material structure that simulate biological ones and additionally provide a direct delivery system. The functionality of nanotechnology for regenerative medicine is primarily due to its small unit size according to the International System of Units, one nanometer is one-billionth of a meter. The unit size allows for the technological apparatus to navigate the bloodstream and target and fix damage cells in tissues.
The future for the total artificial heart with respect to using polyurethanes comes in the form of thermoplastic polyurethane (TPU), also known as polyurethane elastomers that have molecular structures similar to that of human proteins. TPUs have slower protein absorption (protein absorption is the beginning of the blood clotting process) this makes TPUs ideal candidates in the manufacturing of the total artificial heart because it provides more adhesive strength and mimics certain elements within the body. Hence, biomedical polyurethanes can lead the way to eliminate some acute health challenges that the total artificial heart currently faces. By virtue of their range of properties, polyurethanes and their new applications will continue to play an important role in the future of the total artificial heart.
Our own immune system such as macrophages help in restoring the damage in the heart for example, damage caused by myocardial infarction. Macrophages responsibilities are to clear the infarcted area and activate other cells, such as fibroblasts, endothelial cells and progenitor cells to help the healing process of the blood vessels (Mercola et al. 2011). Tissue regenerative in today’s world uses the stem cell technology to repair, replace and regenerate the cells of the injured organ or tissues. It is a combination of engineering principles and life sciences in order to create something that able to proliferate and regenerate as well as sustaining and improving its functions. This purpose can be achieved by applying functional cells, scaffolds supplementary, stimulate the growth and signal molecules to needed areas. The scaffold delivers as physical support for the cells as well as to function as organizer guiding the cell growth and differentiation (Leor et al. 2005).
Yadav, P. R., & Tyagi, R. (2008). Biotechnology of animal tissues. New Delhi, IN: Discovery Publishing House.
The knowledge of thermoplastic elastomers (TP)from blends of NBR and HDPE has occurred as a valuable implement in tai...
Bardone, E., Bravi, M. and Keshavarz, T. (2014). Synthesis and Characterizations of Poly (Lactic Acid) by Ring-Opening Polymerization for Biomedical Applications. 1st ed. [ebook] AIDIC. Available at: http://www.aidic.it/cet/14/38/056.pdf [Accessed 24 Jul.
Polymerization of cyclic esters has attracted a lot of interest for the synthesis of biodegradabale/ biocompatible polymeric materials, such as polylactide, polyglycolide and also other polymer compound such as linear polycarbonate. Ring opening polymerization of cyclic ester compounds is better than step polymerization for obtaining high Mw polymers in a controlled “living” fashion, while avoiding the formation of by-products.
Polymers: A great variety of polymers are used as biomaterials in medicine. Their applications vary from facial prostheses to tracheal tubes, from dentures to hip and knee joints and from kidney and liver parts to heart components. Polymeric materials are also used for medical adhesives and sealants and are also used for coatings that perform a range of functions.
Figure. 2 gives a brief summary of the applications of biomass-derived degradable polymers. Nowadays, there are tremendous interest in research and using of biopolymers in packaging, civil engineering, biomedical and automotive mystery
Lectin belongs to group of structurally diverse proteins and glycoproteins that can bind reversibly to specific carbohydrate residues. After initial mucosal cell binding, lectins can remain on the cell surface or in case of receptor mediated adhesion possibly become internalized via a process of endocytosis. Lectins not only allow targeted specific attachment but also can control the drug delivery of macromolecular pharmaceuticals.
The tack of the UV-crosslinked acrylic adhesives decreased with the increase in the photoinitiator concentration. Polymeric photoinitiators were synthesized using polyacrylates having benzophenone incorporated into their backbones and blended with Hydrogenated rosin epoxy methacrylate (HREM; based on hydrogenated rosin and glycidyl methacrylate) synthesized as a tackifier.6 It was observed that probe tack decreased because of the increased consumption of benzophenone groups with increasing UV dose. Rate of the decrease in the relative benzophenone concentration decreased with increasing hydrogenated rosin content in the PSA blends indicating that the hydrogenated rosin acted as a UV-curing retardant.Reactivity of the functional group, its concentration, the viscosity of the resin, as well as the intensity of the UV-radiation influences the rate of the rate of
Polymers popularly coined as “plastics” have proved their importance in different areas like FMCG, pharma, automobiles, etc. Plastics are versatile materials with unique properties like high strength to weight ratio, good aesthetics; good Processability, balanced engineering properties and optimum cost led its entry into medical