Biomedical application of an enzymatically synthesized biopolyester

Abstract

Polymers have played an integral role in advancing drug delivery technology by providing controlled release of therapeutic agents at fixed doses over long periods of time, cyclic dosing, and adjustable release of both hydrophilic and hydrophobic drugs. Modern advances in drug delivery are now based on the rational design of polymers designed to exert different biological functions. Enzyme-based biopolymer syntheses are needed in order to reduce the toxic accumulations caused by these drug systems in the human body, to minimize their side effects, and their effects on the environment. Unlike synthetic polymers, biopolymers produced naturally using enzymes; They are suitable for medical applications due to their biocompatibility, biodegradability, non-toxicity and ability to adsorb bioactive molecules. The use of these biopolymers in drug delivery systems is possible by turning them into materials such as cast films, microspheres, nanoparticles and nanofibers. Various proteins, drugs and proteins can be easily loaded into microspheres. Therefore, in this study, microspheres consisting of biopolymers loaded with antibacterial agents and drugs will be produced. In this study, polypentadelactone-co-valerolactone copolymer synthesized by the immobilized enzyme. In this study, Candida antarctica B lipase was immobilized to rice husk ash, on which surface modifications were applied using the immobilization methods used in previous studies, primarily to be used in enzymatic polymerization reactions. ω-pentadecalactone-co-δ-valerolactone copolymer was produced by ring-opening polymerization using immobilized enzyme from ω-pentadecalactone and δ-valerolactone at different reaction times and temperatures, using monomer ratios of 75-25%. During support preparation and immobilization, RHA was produced by burning rice husks at 600-650°C for 6 hours. The surface of RHA was then modified using a silanization chemical called 3-aminopropyl triethoxysilane (3-APTES), and functional amine (-NH2) groups were added to the surface. Lipase immobilization was achieved by physical adsorption. Previous scientific investigations attempted to optimize novel immobilized lipases using various 3-APTES concentrations and enzyme loading ratios. These research studies are used as references. After copolymers is produced, they will be formed into microspheres and added with oleuropein as an antibacterial agent and loaded with trans-Chalcone as a drug for use in biomedical fields. A drug delivery system with strong mechanical properties, biocompatible, biodegradable, harmless to the environment and living things will be developed by incorporating the copolymer into the polymer-containing microspheres of the drug and antibacterial agent. ω-Pentadecalactone, or pentadecanolide, is a cyclic ester having a 15-carbon backbone. ω-pentadecalactone may have antibacterial and antioxidant properties. Its potential pharmacological qualities make it an attractive candidate for the development of pharmaceutical formulations and nutraceuticals. δ-valerolactone, a lactone, is employed as a chemical intermediate in several processes, such as polyester manufacturing. Polyvalerolactone is a semi-crystalline aliphatic polyester that is hydrophobic. PVL is a well-known biopolymer that has several applications in medication formulation and delivery systems. PVL-based polymers have been employed as antifungal carriers as well as a hydrophobic block in amphiphilic block copolymers for the in vivo administration of chemotherapeutic medications such as daunorubicin (DNR), doxorubicin (DOX), and others. Microspheres are spherically shaped particles that can vary in size from one to a thousand meters. Microspheres are biodegradable, free-flowing particles made up of proteins or synthetic polymers. They are capable of encapsulating small molecules, proteins, peptides, and nucleic acids. They have various advantages over traditional dosage forms, including increased solubility of poorly soluble pharmaceuticals, protection against enzymatic and photolytic degradation, reduced dosing frequency, greater bioavailability, controlled release profile, dose reduction, and drug toxicities. Oleuropein appears to be an effective antibacterial agent. Oleuropein, the major phenolic component of the olive tree, is a chemical found in the fruit in the early stages of ripening, and its level diminishes as the fruit ripens as it is digested. Recent research indicates that oleuropein possesses anticancer, antiviral, antioxidant, and anti-inflammatory properties. Oleuropein will be employed as an addition in this investigation since it is considered to improve antibacterial activity and cell proliferation. Chalcones are open-chain chemicals found naturally in plants. The chemical structure is composed of two aromatic rings separated by a three-carbon α,β-unsaturated carbonyl system.. Trans-chalcone (TC) has grown in popularity in recent years for its biological properties due to its abundance in nature, simplicity of synthesis, and simple structure. TC has been demonstrated to have anticancer effects against a variety of types. TC is also anti-inflammatory, working by reducing the oxidative stress caused by a variety of inflammatory diseases. Many additional compounds are metabolically activated by TC. It has been demonstrated that these substances have estrogenic action. Due to the estrogenic action of xenobiotic chemicals, animals may experience a variety of negative health impacts, including obesity, accelerated female puberty, a decrease in sperm count, altered sexual behavior and reproductive organs, and an increased risk of certain cancers. Controlling the amount of TC treatment and preventing the buildup of TC molecules in the body are therefore crucial. The aim of this study is to develop a new drug delivery system by loading drug and adding antibacterial agent into the bio-based polymeric structure. Microspheres will be obtained by synthesizing a biocompatible, non-toxic and high molecular weight copolymer by using naturally immobilized enzyme to be compatible with the environment and human body. Controlled drug delivery will be carried out by loading a drug and adding an antibacterial agent to this product. Thus, the side effects of the drug will be reduced and its therapeutic properties will be increased. The lack of research in the literature on the use of oleuropein and transchalcone with microspheres for medical reasons adds to the scientific value of the study. The study's uniqueness stems from the lack of literature on the poly(ω-pentadecalactone-co-δ-valerolactone) copolymer produced by enzymatic polymerization. The copolymer synthesized using a biocatalyst will be loaded with oleuropein and trans-chalcone while microspheres are produced and it will be used as medicine. With this mixture, cell biological compatibility will be ensured and the drug will be ensured to reach the desired area at the desired time. As a result, a new drug delivery system will be created by using natural and synthetic polymers, drugs and antibacterial agents. In the second stage, a ω-pentadecalactone-co-δ-valerolactone copolymer was produced enzymatically using the monomer ratios from earlier research as a reference. The highest molecular weighted sample (Mn = 23722 g/mol) was obtained at 80°C and 24 hour reaction duration with 75% ω-pentadecalactone feed weight ratio and selected for microsphere formation. Therefore, in this work, ω-pentadecalactone-co-δ-valerolactone is synthesized utilizing these values. In the third stage of the study, oleuropein added and transchalcone loaded PDL-VL microspheres was tried to be produced via O/W emulsion method. In order to determine the highest encapsulation efficiency and drug release behavior, combinations of 10, 20 and 40 percent TC, as well as 42.5, 75 and 100 Olu, in proportion to the copolymer mass were examined. It was determined that microspheres produced at 100% Olu:PDL-VL ratio and 20% TC:PDL-VL ratio had the highest Encapsulation Efficiency (%) which it was 81.7 ± 0.5 (%). After microspheres are made, several characterization analysis were applied such as SEM, DSC, TGA, FTIR and XRD in order to understand thermal, mechanical and morphological properties of microspheres. DSC analysis was applied to observe the thermochemical changes of the copolymer and microspheres samples. Melting temperatures and enthalpy values of microspheres were examined according to the previous scientific studies. The fact that no melting peak was observed in both oleuropein and transchalcone samples indicates that PDL-VL/Olu and TC-loaded PDL-VL/Olu microspheres are properly dispersed into the structure as stated in the literature. TGA analyzes were applied in order to analyze the thermal degradation behavior of microspheres and compare with PDL-VL. FT-IR was used as a characterization method to observe the chemical groups indicating the presence of Olu, TC and microspheres. All the characteristic peaks were examined and explained. It was concluded that Olu and TC were encapsulated in the microspheres. In addition to all other analyses, the influence of TC loading on crystallinity and crystalline structures of microspheres was examined using XRD analysis. The Xc values were determined, and distinctive crystalline peaks were investigated. The results were similar with those obtained from the DSC. It can be seen from the SEM images that spherical geometry was found in all microsphere formulations. Antibacterial acitivty tests were also examined and it led to the conclusion that PDL-VL/Olu and TC-loaded PDL-VL/Olu microspheres have antibacterial properties. As a results of cytotoxicity anaylsis, it leads to a reduction in the viability of human breast cancer cell lines (MCF-7), and therefore it is effective and promising for human breast cancer therapy. In this study, pH dependent drug release experiments were performed with two pH values which was 5.6 and 7.4 in order to see drug release behaviour of microspheres produced with different environments. The microsphere formulations improved the total cumulative release of TC, which reached 91.18 % in pH 5.6 media and 85.89 % in pH 7.4 media. The behavior of microspheres' release was based on pH; the more acidic the release medium, the greater the release. In all cases, TC release was carried out for up to 964 hours. Lastly, the release kinetics of the design points were investigated. When the release rate constants were assessed, it was discovered that the release suited the Korsmeyer-Peppas kinetic model, which had the highest correlation coefficient. After all characterization analysis and drug release behaviour were obtained, it can be concluded that the the results of this study point to a potential use for microspheres in the long-term therapy of disease. And, undoubtedly, much more study will be required to assess cytotoxicity, cell survival, and in vivo pharmacokinetics.