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Optical Nanoprobes for Diagnosis
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
R. G. Aswathy, D. Sakthi Kumar
Polyesters exemplify the most extensively employed class of polymers, owing to their biodegradable and biocompatible qualities. These include polylactide (PLA), polyglycolide (PGA), poly(e-caprolactone) (PCL), and poly(g-valerolactone) (PVL), and most of them are generally synthesized by ring-opening polymerization of lactide, lactide/glycolide, e-caprolactone, and gvalero-lactone, respectively. PLGA copolymer of lactide and glycolide is the Food and Drug Administration (FDA) approved polymer for drug delivery applications. Amphiphilic PLGA-b-PEG or PLA-b-PEG copolymers, comprising hydrophobic PLGA or PLA block and a hydrophilic PEG, have been used to prepare NPs, polymersomes, or micelles, where the hydrophobic part (PLGA or PLA) and hydrophilic PEG results in the formation of core and shell of nanocarriers, respectively. PEGylated NPs demonstrate the potential to be functionalized with various ligands, such as small molecules, peptides, antibodies, and aptamers conjugated to PEG chain. There have been several reports on the application of PNPs as diagnostic as well as therapeutic (theragnostic) multifunctional agents. PLGA NPs carrying various drugs (curcumin, paclitaxel, gemcitabine, 5-Fluorouracil (5FU), etc.) with different targeting moieties (folate, aptamer, peptide, transferrin, etc.) against pancreatic as well as breast cancer cells have been reported [175–178].
Marine Adhesive Proteins for Novel Applications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Smit P. Bhavsar, Maushmi S. Kumar, Vandana B. Patravale
Synthetic polyesters have been extensively applied in diverse biomedical applications, especially in tissue engineering due to their good mechanical property, easy producibility and controllable biodegradation (Park et al., 2011). Combining adhesive Dopa derivatives with biocompatible polyesters has led to strong tissue adhesives successfully served as bone glue. There has been synthesis of hyperbranched poly (β-amino ester) with dopamine and triacrylate monomers through a Michael addition reaction, which exhibited 37-kPa adhesion strength to wet tissue surface after crosslinking by fibrinogen within 15 min (Zhang et al., 2014). The mechanical properties of the prepared adhesive were further improved by reinforcement with nano-sized hydroxyapatite particles, and it was demonstrated that the nanocomposite was able to act as a efficient bone adhesive for sternal closure with tunable curing speed and sufficient load-bearing capacity (Zhang et al., 2014). A poly (ester urea)–based adhesive showing adhesive strength comparable with fibrin glue was developed by introducing pendant catechol groups (Zhou et al., 2015), and after the incorporation of poly (propylene glycol) into the backbone, the adhesive was rendered ethanol solubility that is favorable for clinical applications (Zhou et al., 2016). When a plant-based poly (lactic acid) (PLA) was modified with catechol functionality, the biomimetic adhesive possessed strong adhesion strength of 2.6 MPa in air and 1.0 MPa under wet conditions to aluminum substrates (Jenkins et al., 2012).
Vaccine Adjuvants in Immunotoxicology
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
Nanoparticles are manufactured using albumin, collagen, starch, chitosan, and dextran out of natural polymers and polymethylmethacrylate, polyesters, polyanhydrides, and polyamides among synthetic polymers (Li et al. 2014). There are biodegradable or non-biodegradable polymers. Non-biodegradable polymers may cause unexpected effects by accumulation in the body. In the vaccine studies, the characteristics such as toxic effects of the polymer on the organism, antigen release speed capacity, stability status under storage conditions, and stability in the in vivo conditions should be taken into account in making a decision for an ideal polymer carrier system (Skwarczynski and Toth 2011, 2016). The comprehensive toxicity tests for several synthetic polymers such as polyesters, polylactic acid (PLA), polyglycolic acid, and their copolymers poly(lactic-co-glycolic acid) (PLGA) have been carried out and they are FDA-approved for use in humans (Li et al. 2014; Cordeiro and Alonso 2016). The most commonly used biodegradable polymers are PLA, PLGA, polyglutamic acid (PGA), polycaprolactone (PCL), and polyhydroxybutyrate. PLGA is the most frequently used polymer in the nanoparticle studies (Li et al. 2014). Skwarczynski and Toth (2011) have reported in their study that MUC-1 peptide vaccine assembled into PLGA nanoparticle carrier system accompanied with adjuvant MPLA created immune response by inducing T cells. However, it has been noted in the same article that need for use of adjuvant in the PLGA-based systems still continues (Skwarczynski and Toth 2011).
Polyvinylidene Fluoride Mesh Use in Laparoscopic Ventral Mesh Rectopexy in Patients with Obstructive Defecation Syndrome for the First Time
Published in Journal of Investigative Surgery, 2021
Mahdi Alemrajabi, Behnam Darabi, Behrouz Banivaheb, Nima Hemmati, Sepideh Jahanian, Mohammad Moradi
Interestingly, polypropylene as one of the mesh materials used in trials, had the highest overall complication rates. Evans et al. reported a patient with a perforated diverticulitis who expired afterward. In recent years, the safety of synthetic mesh use in LVMR became questionable, especially the polypropylene mesh. One of the major complications of polypropylene mesh is erosion of the surrounding tissues, especially when used in pelvic organ prolapse and rectopexy [26]. Also, the use of polyester mesh is an independent risk factor of mesh-related complications [27]. Biological meshes seem to be a good option with low complication rate, but relatively expensive and not available in all countries [28]. Systematic reviews reported mesh-related complications for biological meshes [11, 12]. Also, the price of biological meshes are higher and it was suggested that these meshes should be used in patients with higher risk of complications such as fistula formation, pelvic infection, diverticular disease, irritable bowel syndrome, history of pelvic radiotherapy, steroid use or previous mesh-related complication [12]. Therefore, exploring new options seems to be mandatory.
Impaired exercise capacity in electrostatic polyester powder paint workers
Published in Inhalation Toxicology, 2021
Ukbe Sirayder, Deniz Inal-Ince, Cihangir Acik, Ferhan Soyuer
Electrostatic powder paints (EPP) contain polyester, which is a hydrocarbon. It is a polymer that is formed by melting at a high temperature of petroleum and produced ‘terephthalic acid’ and ‘ethyl glycol,’ and it is a carcinogenic substance (Pang et al. 2016). Polyester is used in electrostatic paint production due to its electrostatic properties. Polyesters are known to cause various skin diseases (Meyers 2010). In addition, it decreases the progesterone ratio in pregnant women due to its electrostatic effect and causes miscarriage. In male subjects, the use of polyester underwear has been reported to reduce sperm count and quality. The inhalation of polyester, which has serious side effects even in contact with the skin, is hazardous (Dale et al. 2014). When animal experiments conducted to investigate the effectiveness of polyester are examined, it is seen that exposure to polyester causes damage to the lung tissue the most. At 13 weeks, it has been shown to cause an increase in the weight, the number of macrophages and inflammatory cytokines of the affected lung tissue (Katz et al. 1997). In addition to the polyester in powder paints, organic, metallic, and plastic pigments, binders, and thinners are used. Each of these may accumulate in the lungs as a result of inhalation and may cause occupational lung diseases (Meyers 2010).
Nose-to-brain delivery of borneol modified tanshinone IIA nanoparticles in prevention of cerebral ischemia/reperfusion injury
Published in Drug Delivery, 2021
Luting Wang, Lin Xu, Junfeng Du, Xiao Zhao, Mei Liu, Jianfang Feng, Kaili Hu
TSA is the major active ingredient of a Traditional Chinese Medicine (TCM) Salvia miltiorrhiza, which has been widely used for the treatment of cerebrovascular diseases (Han et al., 2008). Modern clinical and pharmacological studies have shown a variety of activities of TSA such as significant inhibition of the degree of peroxidation, decrease the toxicity of excitatory amino acid, inhibit Ca2+ overload, decrease NO release, inhibit mitochondrial damage, decrease oxygen free radicals level, regulate the immunoinflammatory process, and inhibit apoptosis (Dong et al., 2018). Besides the notable curative effects for cardiovascular and cerebrovascular diseases, TSA also indicates various activities that might be effective in protection for CIRI (Tang et al., 2010; Liu et al., 2010a, 2011). However, due to the poor solubility of TSA, rapid plasma clearance, and P-gp efflux, it is difficult to pass through the blood–brain barrier (BBB), which greatly limits its therapeutic effect on CIRI. In this study, polymeric NPs were chosen to improve the brain targeting of TSA after IN administration. The variability of polymer carrier can give drug delivery system many new characteristics. Polyester materials are widely used because of their biodegradability, good biocompatibility, and safety. Free design of polymer chain length can produce different particle size, drug delivery capacity, and biological effects.