Poly Ester Amide Research Articles

Random poly(ε‐caprolactone‐L‐alanine) by direct melt copolymerization

AbstractA series of random polyesteramides (PEAs) with a range of molar composition from 90/10 to 50/50 were synthesized by direct melt polycondensation of ε‐caprolactone and l‐alanine. Their structure was fully characterized by Fourier transform IR and NMR spectroscopy. The resulting copolymers are completely amorphous with the exception of PEA‐90/10 which possesses a semicrystalline structure. These PEAs present increasing glass transition temperatures at increasing l‐alanine contents and exhibit fairly good thermal stability with 10% mass loss temperatures reaching 315 °C. © 2020 Society of Industrial Chemistry

Biodegradable Nanoparticles Based on Pseudo-Proteins Show Promise as Carriers for Ophthalmic Drug Delivery.

Purpose: Drug delivery to treat ocular diseases still is a challenge in ophthalmology. One way to achieve drug delivery that is investigated currently is topical administration of drug-loaded polymeric nanoparticles (NPs) that are able to penetrate ocular barriers. The purpose of this study was optimal preparation of NPs made from pseudo-proteins and evaluation of their ability to penetrate ocular tissues. Methods: Biodegradable NPs of various types were prepared by nanoprecipitation of pseudo-protein composed of l-leucine (L), 1,6-hexanediol (6), and sebacic acid (8) (8L6). Arginine-based cationic polyester amides 8R6 and comb-like polyester amide containing lateral PEG-2000 chains along with 8L6 anchoring fragments in the backbones were used to construct positively charged and PEGylated NPs. They were loaded with fluorescein diacetate (FDA) or rhodamine 6G (Rh6G) as fluorescent probes. Suspensions of the NPs were given to cultivated microglial cells and retinal pigment epithelial (RPE) cells as well as topically on eyes of C57BL/6 mice. Penetration of NPs into the eyes was checked by fluorescence analysis. Results: NPs were prepared, and their properties were characterized. Cultured microglial cells and RPE cells took up the NPs. After topical administration, penetration of NPs into the cornea of the eyes was clearly seen. Small amounts of fluorescent dyes were also found in the lens, the retina, and the sclera depending on the type of NPs. Conclusions: The results showed that the new NPs penetrate ocular tissues after topical administration and are internalized by the cells. This raises confidence that the NPs may be useful carriers of therapeutic agents for ocular delivery.

Simultaneous monitoring of the bioconversion from lysine to glutaric acid by ethyl chloroformate derivatization and gas chromatography-mass spectrometry

Glutaric acid is a precursor of a plasticizer that can be used for the production of polyester amides, ester plasticizer, corrosion inhibitor, and others. Glutaric acid can be produced either via bioconversion or chemical synthesis, and some metabolites and intermediates are produced during the reaction. To ensure reaction efficiency, the substrates, intermediates, and products, especially in the bioconversion system, should be closely monitored. Until now, high performance liquid chromatography (HPLC) has generally been used to analyze the glutaric acid-related metabolites, although it demands separate time-consuming derivatization and non-derivatization analyses. To substitute for this unreasonable analytical method, we applied herein a gas chromatography - mass spectrometry (GC-MS) method with ethyl chloroformate (ECF) derivatization to simultaneously monitor the major metabolites. We determined the suitability of GC-MS analysis using defined concentrations of six metabolites (l-lysine, cadaverine, 5-aminovaleric acid, 2-oxoglutaric acid, glutamate, and glutaric acid) and their mass chromatograms, regression equations, regression coefficient values (R2), dynamic ranges (mM), and retention times (RT). This method successfully monitored the production process in complex fermentation broth.

Novel Polyester Amide Membranes Containing Biquinoline Units and Complex with Cu(I): Synthesis, Characterization, and Approbation for n-Heptane Isolation from Organic Mixtures.

The wide possibilities of designing a chemical structure and creating complexes with transition metals make polymers of heteroaromatic structure interesting objects, from both scientific and practical aspects. In this work, modern biquinoline-containing polymers, namely polyester amide (PEA) and its metal–polymer complex (PEA–Cu(I)), were synthesized and used to form dense flat membranes. A comparative study of their morphology, same physical properties (density, free volume, and contact angles), and thermomechanical characteristics was carried out. The transport properties of the modern membranes were studied during pervaporation, to solve a problem of n-heptane isolation from its binary mixtures with thiophene and methanol. It was shown that only the PEA membrane is selective for the separation of thiophene impurities from the mixture with n-heptane. In pervaporation of methanol/n-heptane mixture, the РЕА–Cu(I) membrane exhibits significantly higher pervaporation separation index, as compared with that of the РЕА membrane.

Fatty acid based novel precursors for polyesteramide hot melt adhesive

Polyesteramide (PEA) based hot melt adhesive (HMA) was successfully designed containing a high content of renewable mass. The PEA HMA was synthesized based on dimer acid (DA), catechol, ethylenediamine (EDA), ricinoleic acid amide (RA amide) which was synthesized by using ricinoleic acid and diethanolamine. RA amide was reacted with dimer acid with a varying concentration of RA amide by 5%, 10%, 15% and 20% on a molar basis. Catechol was further added on the molar basis of 10%, 20%, and 30% as a partial replacement of ethylenediamine. The effect on the properties of the hot melt adhesive, such as mechanical properties: tensile strength, shore D hardness, elongation at break; thermal properties: glass transition temperature (Tg), melting temperature (Tm), heat of crystallization (Hc), crystallization temperature (Tc); adhesion properties: lap shear strength (LSS) and T-peel strength (TPS); rheological properties and degree of crystallinity was investigated. It was observed that the mechanical and thermal properties are increased with increasing concentration of RA amide and catechol. These HMA materials could hold potential for sustainability and high adhesive performance.

Synthesis, characterization and evaluation of long-acting hyperbranched cationic polymer clay stabilizer used in water flooding

In the process of waterflooding development, it is of great importance to prevent the clay from hydration swelling and migration dispersion for protecting the formation and improving the water flooding efficiency. For those reasons, we successfully synthesized a cationic clay stabilizer (HBP-QAT) through melting polycondensation and cationic modification with maleic anhydride, diethanolamine, epichlorohydrin, triethylamine, and trimethylolpropane as monomers and p-toluene sulfonic acid as a catalyst. The chemical structure, cation degree, and molecular weight of HBP-QAT were studied by using FTIR, 1H NMR, sodium tetraphenylborate (STBP) back titration, and gel permeation chromatography (GPC). The obtained results showed that HBP-QAT was a hyperbranched unsaturated polyester amide with a low molecular weight and a high cation degree, with corresponding values of 28400, and 44.2%, respectively. The clay stability and durability of HBP-QAT were evaluated by linear anti-swelling, water flushing, and cutting rolling recovery tests. The obtained results showed that HBP-QAT has an excellent anti-washing capacity and a long-term inhibition effect. The initial anti-swelling rate of 1.0 wt% HBP-QAT reached 92.37%, and the anti-swelling rate of 1.0 wt% HBP-QAT also remained at 85% after flushing 10 times with water. Besides, the two cutting rolling recoveries exceed 72%. Most importantly, the inhibition mechanism of HBP-QAT was studied by zeta potential, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and contact angles analyses, and thus we proposed an inhibition mechanism, presenting as follows. HBP-QAT inhibited the clay hydration swelling by neutralizing negative charges on the surface of the clay particles to compress the electric double layer, strongly adsorbing on the surface of the clay particles, and forming a waterproof polymer membranes, restraining water of intrusion into the clay interlayer.

Preparation and properties of anion-nonionic hyperbranched surfactants for high salinity and temperature reservoirs

A series of anion-nonionic hyperbranched surfactants HPSA were prepared by grafting the N-lauryl-monoamido sulfosuccinic acid onto hydroxyl-terminated hyperbranched polyamide ester (HP). The optimum grafting condition was obtained by single-factor experiments when the mole ratio of HP and N-lauryl-monoamido sulfosuccinic acid was 1:5. The molecular structure of HPSA-5 were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and gel permeation chromatograph. Furthermore, the wettability, surface activity and emulsifying ability of the prepared surfactant were studied. The results showed that HPSA-5 solution had good potential on change of wettability. Surface activity studies showed that HPSA-5 was temperature-resistant and salt-tolerant capacity of 140 °C and ρ(NaCl) = 2 × 105 mg/L, ρ(CaCl2) = 1.5 × 104 mg/L, respectively. In the heat aging experiment (under the temperature of 120 °C and the NaCl of 105 mg/L for 12 hours), the surface tension of HPSA-5 were almost unchanged. The salt tolerence of 0.3 g/L HPSA-5 was superior to 0.3 g/L SDS and 0.3 g/L OP-10 at the ability of emulsifying Tahe crude oil (China, Xinjiang) at 120 °C. The result of the sandpack model crude oil displacement experiments showed that 1.5 g/L HPSA-5 could further increase the crude oil recovery to 10.27%, compared with 6.44% crude oil recovery for 0.6 g/LSDS + 0.9 g/L OP-10 after water flooding.

Applicability of a Modified Rat Model of Acute Arthritis for Long-Term Testing of Drug Delivery Systems.

Episodes of inflammation and pain are predominant features of arthritic joint diseases. Drug delivery systems (DDS) could reduce inflammation and pain long-term without chances of infection upon multiple injections. To allow for long-term evaluation of DDS, we modified a previously published acute arthritis model by extending follow-up periods between flare-ups. Unilateral synovial inflammation of the knee was induced by intra-articular injection of streptococcal cell wall peptidoglycan polysaccharide (PGPS), and flare-ups were induced by intravenous PGPS injections every 4 weeks for a total duration of 84 days. In PGPS-reactivated animals, joint swelling, pain behavior, post mortem synovitis, and osteophyte formation were notable features. Hepatitis, splenitis and inflammation of non-primed joints were observed as systemic side effects. To test the applicability of the modified arthritis model for long-term testing of DDS, the duration of anti-inflammatory and analgesic effects of a corticosteroid released from two different polymer-based platforms was evaluated. The current modified arthritis model has good applicability for testing of DDS for a prolonged period of time. Furthermore, the novel autoregulatory polyesteramide (PEA) microsphere platform releasing triamcinolone acetonide (TAA) was benchmarked against poly lactic-co-glycolic acid (PLGA) and reduced joint swelling and pain behavior more potently compared to TAA-loaded PLGA microspheres.

Hyperbranched polymer–silver nanohybrid induce super antibacterial activity and high performance to cotton fabric

Herein we present a novel approach for synthesis, characterization and application of a benign hyperbranched polyester amide–silver nanohybrid (Ag/HBPEA). The Ag/HBPEA is developed through three distinct steps. The first step involves amidation reaction of diethanol amine and maleic anhydride to yield AB2 monomer (adduct 1). The second step comprises reaction of adduct 1 with trimethylol propane in presence of catalyst to yield HBPEA. The third step entails reduction of silver nitrate by sodium borohydride reductant to effect in situ formation of AgNPs which are stabilized by HBPEA, leading ultimately to Ag/HBPEA nanohybrid. Both Ag/HBPEA nanohybrid and HBPEA are independently applied to cotton fabrics as per the conventional pad-dry-cure technique. To this end, through investigations into the structures of Ag/HBPEA nanohybrid and HBPEA stabilizer before and after application to cotton fabric using advanced techniques emphasize the Ag/HBPEA nanohybrid as multifunctional finishing agent rather than a super antibacterial activity of the cotton fabrics after treatment with Ag/HBPEA nanohybrid speaks of this. Current research generally addresses green chemistry because treatments involved therein are based on green basics and practices.

Intra-articular injection of triamcinolone acetonide releasing biomaterial microspheres inhibits pain and inflammation in an acute arthritis model

Inflammation of the synovium and joint capsule is a main driver of pain in an osteoarthritic (OA) joint. Triamcinolone acetonide (TAA) is a classical corticosteroid that reduces synovitis and alleviates pain, albeit transiently. Biomaterial-based local TAA release may prolong the suppression of pain without the need for multiple injections. Polylactic-co-glycolic acid (PLGA) formulations of TAA prolong OA pain relief to a limited extent. A novel polyesteramide (PEA) microsphere platform allows for extended release in the OA joint for over 3 months. To evaluate their effect on pain and inflammation, TAA-loaded microspheres were intra-articularly delivered to the knee joint in a rat model of acute arthritis induced by intra-articular injection of streptococcal cell wall peptidoglycan-polysaccharide (PGPS) and subsequent flare-ups by intravenous PGPS injections. PEA-loaded microspheres were benchmarked with TAA-loaded PLGA microspheres and bolus TAA injection. TAA treatments were injected intra-articularly before the first induced flare-up. TAA-loaded PEA and PLGA microspheres reduced joint swelling and signs of pain-like behavior over the entire study period, as assessed by weight bearing and referred mechanical hypersensitivity, whereas bolus suspension was effective for a shorter time period. TAA-loaded PEA microspheres reduced lameness to a greater extent than TAA-loaded PLGA microspheres. In conclusion, a single intra-articular injection of TAA-loaded PEA microspheres reduced joint swelling and induced longer pain relief compared to bolus injection. Hence relief of inflammation and pain by PEA-based delivery of TAA may prove to be effective and durable.

Waterborne reduced graphene oxide dispersed bio-polyesteramide nanocomposites: an approach towards eco-friendly anticorrosive coatings

RGO dispersed waterborne soy polyester amide nanocomposites were formulated utilizing a solventless VOC free green approach for use as low cost anticorrosive coatings.

Synthesis of biobased polyols using algae oil for multifunctional polyurethane coatings

Renewable sources – namely, algae oil and diacids – were used for the synthesis of alkyd (ALK) and polyesteramide (PEA) polyols. The prepared polyols were characterised by Fourier transform infrared and nuclear magnetic resonance techniques and size exclusion chromatography analysis. After reaction with diisocyanate, polyols were converted to polyurethane (PU) coatings, which were then characterised by X-ray diffraction, differential scanning calorimetry and thermogravimetric analysis. The biocidal activities of the films were evaluated against Gram-negative (Escherichia coli ) and Gram-positive bacteria (Staphylococcus aureus) by using the turbidity method as well as by observation of film degradation or biofilm formation by bacteria on the surface of a metal tray by using scanning electron microscopy. The PUs obtained using ALK and PEA showed better antimicrobial properties compared with PUs based on algae oil fatty amide (AOFA), monoglyceride (MG) and even an uncoated mild steel (MS) panel. The anticorrosion properties of PU coatings were evaluated by the potential dynamic polarisation (PDP) method in a 3·5 wt% sodium chloride (NaCl) corrosive media. All coated samples (ALK and PEA) showed good barrier properties against corrosion compared with AOFA, MG and the uncoated MS panel. The prepared algae-oil-based PU coatings showed better chemical, mechanical, water-repellent, antimicrobial, anticorrosive and thermal properties.

Biodegradable amino acid-based poly(ester amine) with tunable immunomodulating properties and their in vitro and in vivo wound healing studies in diabetic rats’ wounds

The objective of this study is to design a new family of biodegradable synthetic polymeric biomaterials for providing a tunable inhibition of macrophage’s nitric oxide synthase (NOS) pathway. l-Arginine (Arg) is the common substrate for NOS and arginase. Both two metabolic pathways participate in the wound healing process. An impaired wound healing, such as diabetic or other chronic wounds is usually associated with an overproduction of NO by macrophages via the NOS pathway. In this study, a new family of l-nitroarginine (NOArg) based polyester amide (NOArg-PEA) and NOArg-Arg PEA copolymers (co-PEA) were designed and synthesized with different composition ratios. The NOArg-PEA and NOArg-Arg co-PEAs are biodegradable (more than 50% degradation in vitro in 4 days at 37 °C), biocompatible and did not activate the resting macrophage immune response per se. When classically activated or alternatively activated macrophages (CAM/AAM) were incubated with NOArg-PEA and NOArg-Arg co-PEAs, the treatments decreased the NO production of CAM, increased the arginase activity in both CAM and AAM, increased TGF-β1 production of CAM to various degrees and had no significant effect on TNF-α production. Diabetic rat models were used to evaluate the efficacy of NOArg-PEA and NOArg-Arg co-PEAs on wound healing. Diabetic rats treated with 2-NOArg-4 PEA, 2-NOArg-4-Arg-4 20/80, and 2-NOArg-4-Arg-4 50/50 biomaterials achieved 40%–80% faster-wound healing when compared with the control on day 7. The data from the histological and immunohistochemical analysis showed that the 2-NOArg-4-Arg-4 20/80 and 2-NOArg-4-Arg-4 50/50 treatments led to more AAM phenotypes (CD206) and arginase I production in wound tissue than the control during the first 7 days, i.e., suggesting pro-healing wound microenvironment with improved re-epithelialization of wound healing. A similar trend was retained until day 14. The 2-NOArg-4-Arg-4 20/80 and 2-NOArg-4-Arg-4 50/50 treatments also increased the collagen deposition and angiogenesis in the healing wound between day 7 and day 14. Both in vitro and in vivo data of this study showed that this new family of NOArg-Arg co-PEA biomaterials have the potential as viable alternatives for treating impaired wound healing, such as diabetic or other types of chronic wounds. Statement of SignificanceDiabetic or other chronic wounds is usually associated with an overproduction of NO and pro-inflammatory signals by macrophages. Arginine supplement or NOS inhibitors administration failed to achieve an expected improved wound healing because of the dynamic complexity of arginine catabolism, the difficulty in transition from pro-inflammatory to pro-healing, and the short-term efficacy. We designed and synthesized a new family of water-soluble and degradable nitroarginine-arginine polyester amides to rebalance NOS/arginase metabolism pathways of macrophages. They showed tunable immunomodulating properties in vitro. The in vivo studies were performed to evaluate their efficacy in accelerating the healing. These new biomaterials have the potential as viable alternatives for treating impaired wound healing. The general audience of Acta Biomaterialia should be interested in these findings.

Hyperbranched unsaturated polyester amide synthesized by two-step method

PurposeHyperbranched poly(ester-amide)s (HPEAs) have been synthesized from diethanolamine and maleic anhydride with ethylene glycol as a core monomer by using a two-step method, which are marked as Hupea polymers, and dehydration was carried out in xylene under reflux.Design/methodology/approachIn comparison with Hupea polymers was synthesized by one-pot method, Hupea polymers synthesized by two-step method has different structure and rheological properties. The intermediate monomer and the resulting polymer are characterized by FTIR and NMR spectroscopies.FindingsAll of Mw, Mn and Mw/Mn of the hyperbranch polymers decrease with the core/monomer molar ratio increasing. The intrinsic viscosity ([η]) of the polymers decreases with Mw increasing in the investigated range of Mw and scales as [η]∼Mw-0.82, which implies that the molecular weight grew faster with core/monomer molar ratio decreasing than the volume in the investigated range of core/monomer molar ratio.Research limitations/implicationsThe hydrodynamic radius was calculated by using Einstein’s equation and scales as Rh ∼ Mw0.061, and the lower exponent reveals the slow growth in the volume of Hupea molecule. In addition, the viscosity of Hupea polymer in concentrated aqueous solution is independent of shear rate and slightly dependent on molecular weight.Practical implicationsHyperbranched poly(ester-amide)s (HPEAs) were synthesized by using a two-step method, which had different structure and rheological properties.Originality/valueHupea polymers show different features from Hupea polymers in structure and rheological properties, which revealed that the synthesis process of HPEA has effect on its performance.

Eco-friendly waterborne coating from bio-based polyester amide resin

The vegetable oil-based waterborne polyurethane coatings have gained significant interest due to low volatile organic compounds, and hence, this has been considered as a proper substitute to the commonly used solvent-borne coating systems. In the present work, we have developed the polyurethane coatings from diethanolamide of fatty acid and dicarboxylic acid (sebacic acid and succinic anhydride)-based poly(esteramide) resin as a diol along with 2,2′-dimethylol propionic acid and isophorone diisocyanate. The chemical structure of bio-based diol and PU coatings was elucidated by FTIR and 1H NMR spectroscopy. The polyurethane dispersions (PUDs) prepared were analysed by particle size analysis and stability. The mahua oil-based PUDs were coated on the metal panels and the cured material obtained was characterized by the physico-mechanical, chemical resistance and the thermal properties which were compared with the petroleum resource-based PUDs. The PUD coatings showed good physico-mechanical properties, chemical resistance and thermal stability. Hence, the dispersion prepared from bio-based diols may find application as eco-friendly coatings.

A novel polyesteramide thin film composite nanofiltration membrane prepared by interfacial polymerization of serinol and trimesoyl chloride (TMC) catalyzed by 4‑dimethylaminopyridine (DMAP)

In order to integrate the advantages of polyamide thin film composite (TFC) nanofiltration (NF) membranes and that of polyester TFC NF membranes, a novel polyesteramide (PEA) TFC NF membrane was prepared by interfacial polymerization between serinol and trimesoyl chloride (TMC) and catalyzed by 4-dimethylaminopyridine (DMAP) on a flat-sheet polyethersulfone (PES) substrate membrane. The membrane performance was maximized by optimizing different preparation parameters. The reaction process was divided into four basic patterns. X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy confirmed the membrane had a partially cross-linked active layer that contained ester bonds, amide bonds and residual hydroxyl groups. Morphology analysis showed the surface of the PEA-TFC-NF membrane was grainy, which was different from the typical polyamide membranes. The contact angle and zeta potential measurements confirmed the PEA-TFC-NF membrane was highly hydrophilic and negatively charged across the entire pH range tested. The optimized PEA-TFC-NF membrane had a MWCO of 474Da and water permeability of 6.0Lm−2h−1bar−1 at 0.5MPa and 25°C. The membrane salt rejections followed the order of Na2SO4 > MgSO4 > NaCl > MgCl2, which were 96.27%, 83.92%, 58.68% and 28.76%, respectively. Moreover, the PEA-TFC-NF membrane displayed good antifouling ability.

SOME WATER-SOLUBLE POLYMERS AS CORROSION INHIBITORS FOR CARBON STEEL IN ACIDIC MEDIUM

Encouraged by the excellent performance of organic polymers as scale inhibitors and anticorrosive coatings, we reasoned that polymers with properly designed structures might also be used as efficient water-soluble corrosion inhibitors. New kind of water soluble hyperbranched polyamide ester (HPAE) synthesized using trimethylol propane as a precursor via Michael addition reaction with diethanolamine. The chemical structure of the prepared polymers was determined by FT-IR. The inhibitive effect of HPAE on the corrosion of steel in 1 M HCl solution has been investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The results indicated that HPAE inhibited the corrosion of steel and the extent of inhibition increased with HPAE concentrations. Potentiodynamic polarization data suggests mixed-mode of corrosion inhibition.

Synthesis and characterization of poly (ε-caprolactam-co-lactide) polyesteramides using Brønsted acid or Brønsted base organocatalyst

Polyesteramides (PEAs) are considered intriguing materials due to the combination of the favorable degradable capacity of aliphatic polyesters given by the hydrolizable ester groups and the desirable thermal and mechanical behavior of polyamides given by the amide groups. Between polyamides and polyester families, poly(ε-caprolactam) and poly(l-lactide) stand out due to their commercial value and outstanding properties. Nevertheless, to date these two monomers have not been co-polymerized due to their different reactivities. In this work, we report for the first time, up to our knowledge, the synthesis of poly(ε-caprolactam-co-l-lactide) copolymers with different compositions. Two different catalysts: (a) Brønsted acid ionic liquid 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate (BAIL) and (b) Brønsted base P4-t-Bu have been explored. In the presence of Brønsted acid the l-lactide reactivity is higher than the ε-caprolactam while in the presence of Brønsted base the opposite behavior is observed. Using Kelen-Tudos method the monomer reactivity ratios are calculated and obtained as rCLa=0.39 and rLA=1.6 and rCLa=2.2 and rLA=0.1 using BAIL and P4-t-Bu, respectively. These differences in the monomer reactivity ratios give us the possibility to create copolymers with different chain microstructure depending on the employed catalyst between 2 and 9kDa. Thus, using P4-t-Bu random copolymers can be obtained at high l-lactide concentration and blocky character copolymers at high ε-caprolactam concentration. Meanwhile, using BAIL catalyst random like copolymers are obtained at high ε-caprolactam contents and blocky character at high l-lactide contents.

Polyester amide based polyurethane coatings from algae oil and their larvicidal, anti-ant properties

Abstract Larvicides play a vital role in controlling mosquitoes in their breeding sites. The present study was carried out to establish the larvicidal and anti-ant activities of polyester amide based polyurethane coating from algae oil against mosquitos’ larvae and red ants responsible for diseases of public health importance. The polyester amide synthesized by N , N -bis (2-hydroxy ethyl) algae oil fatty amide and ethylene diamine tetra acetic acid through condensation polymerization. After that resin cured with MDI to obtained polyurethane coatings. Coating performance was tested. Larval mortality of mosquito’s larvae was observed at 12, 24 and 48 h of exposure to different weight of PU films. The efficacy of polyurethane coating films against mosquitos’ larvae (LC 50 and LC 90 ; 5.35 and 17.15 mg/mL) respectively were observed by probit analysis while the mortality of ants also observed at 2, 4, 6 and 12 h of exposure to PU coatings. Polyurethane coatings can be recommended effectively in mosquitos and ants controlling practices. The cytocompatibility study was also carried out and study shows good results.

Prolonged inhibition of inflammation in osteoarthritis by triamcinolone acetonide released from a polyester amide microsphere platform

Controlled biomaterial-based corticosteroid release might circumvent multiple injections and the accompanying risks, such as hormone imbalance and muscle weakness, in osteoarthritic (OA) patients. For this purpose, microspheres were prepared from an amino acid-based polyester amide (PEA) platform and loaded with triamcinolone acetonide (TAA). TAA loaded microspheres were shown to release TAA for over 60days in PBS. Furthermore, the bioactivity lasted at least 28days, demonstrated by a 80–95% inhibition of PGE2 production using TNFα-stimulated chondrocyte culture, indicating inhibition of inflammation. Microspheres loaded with the near infrared marker NIR780-iodide injected in healthy rat joints or joints with mild collagenase-induced OA showed retention of the microspheres up till 70days after injection. After intra-articular injection of TAA-loaded microspheres, TAA was detectable in the serum until day seven. Synovial inflammation was significantly lower in OA joints injected with TAA-loaded microspheres based on histological Krenn scores. Injection of TAA-loaded nor empty microspheres had no effect on cartilage integrity as determined by Mankin scoring. In conclusion, the PEA platform shows safety and efficacy upon intra-articular injection, and its extended degradation and release profiles compared to the currently used PLGA platforms may render it a good alternative. Even though further in vivo studies may need to address dosing and readout parameters such as pain, no effect on cartilage pathology was found and inflammation was effectively lowered in OA joints.