Search results for "glycolic acid"
showing 10 items of 46 documents
PLGA Nanoparticles Co-encapsulating NY-ESO-1 Peptides and IMM60 Induce Robust CD8 and CD4 T Cell and B Cell Responses
2021
Contains fulltext : 232076.pdf (Publisher’s version ) (Open Access) Tumor-specific neoantigens can be highly immunogenic, but their identification for each patient and the production of personalized cancer vaccines can be time-consuming and prohibitively expensive. In contrast, tumor-associated antigens are widely expressed and suitable as an off the shelf immunotherapy. Here, we developed a PLGA-based nanoparticle vaccine that contains both the immunogenic cancer germline antigen NY-ESO-1 and an α-GalCer analog IMM60, as a novel iNKT cell agonist and dendritic cell transactivator. Three peptide sequences (85-111, 117-143, and 157-165) derived from immunodominant regions of NY-ESO-1 were se…
Amorphous polyphosphate/amorphous calcium carbonate implant material with enhanced bone healing efficacy in a critical-size defect in rats
2016
In this study the effect of amorphous calcium carbonate (ACC) microparticles and amorphous calcium polyphosphate (polyP) microparticles (termed aCa-polyP-MP) on bone mineral forming cells/tissue was investigated in vitro and in vivo. The ACC particles (termed ACC-P10-MP) were prepared in the presence of Na-polyP. Only the combinations of polyP and ACC microparticles enhanced the proliferation rate of human mesenchymal stem cells (MSCs). Gene expression studies revealed that ACC causes an upregulation of the expression of the cell membrane-associated carbonic anhydrase IX (CA IX; formation of ACC), while the transcript level of the alkaline phosphatase (ALP; liberation of orthophosphate from…
Robust Antigen-Specific T Cell Activation within Injectable 3D Synthetic Nanovaccine Depots
2021
Contains fulltext : 244693.pdf (Publisher’s version ) (Open Access) Synthetic cancer vaccines may boost anticancer immune responses by co-delivering tumor antigens and adjuvants to dendritic cells (DCs). The accessibility of cancer vaccines to DCs and thereby the delivery efficiency of antigenic material greatly depends on the vaccine platform that is used. Three-dimensional scaffolds have been developed to deliver antigens and adjuvants locally in an immunostimulatory environment to DCs to enable sustained availability. However, current systems have little control over the release profiles of the cargo that is incorporated and are often characterized by an initial high-burst release. Here,…
Poly(glycolide) multi-arm star polymers: Improved solubility via limited arm length.
2010
Due to the low solubility of poly(glycolic acid) (PGA), its use is generally limited to the synthesis of random copolyesters with other hydroxy acids, such as lactic acid, or to applications that permit direct processing from the polymer melt. Insolubility is generally observed for PGA when the degree of polymerization exceeds 20. Here we present a strategy that allows the preparation of PGA-based multi-arm structures which significantly exceed the molecular weight of processable oligomeric linear PGA (<1000 g/mol). This was achieved by the use of a multifunctional hyperbranched polyglycerol (PG) macroinitiator and the tin(II)-2-ethylhexanoate catalyzed ring-opening polymerization of gly…
Stopped-flow Fourier-transform infra-red spectrometric speciation of glycolic and lactic acids in cosmetic formulations
2001
The dermatological activity of cosmetic formulations containing alpha-hydroxyacids depends on their different chemical forms, and it is therefore useful to determine these species in the finished products. In the present report a new procedure for studying the protonation equilibria of glycolic and lactic acids by stopped-flow Fourier-transform infra-red (FTIR) spectrometry is described. The procedure was validated for use in the speciation of glycolic and lactic acids in cosmetic formulations, with preferential attention given to glycolic acid, which is the most widely used. Species of these alpha-hydroxyacids can be approximately determined at different pHs and the total content of each a…
Synthesis of the aggregation pheromone of the Colorado potato beetle from its degradation product
2015
Incubation of the Colorado potato beetle aggregation pheromone, (S)-1,3-dihydroxy-3,7-dimethyl-6-octen-2-one, with antennal or leg extracts from this beetle gave 6-methyl-5-hepten-2-one as the major product. This ketone was used as a substrate in a stereoselective synthesis of the pheromone. It was attached to the butanediacetal of glycolic acid with good stereoselectivity and the desired isomer was further enriched by purification of the product of this reaction on silica gel.
Hyaluronic acid and its derivatives in drug delivery and imaging: Recent advances and challenges.
2015
Hyaluronic acid (HA) is a biodegradable, biocompatible, nontoxic, and non-immunogenic glycosaminoglycan used for various biomedical applications. The interaction of HA with the CD44 receptor, whose expression is elevated on the surface of many types of tumor cells, makes this polymer a promising candidate for intracellular delivery of imaging and anticancer agents exploiting a receptor-mediated active targeting strategy. Therefore, HA and its derivatives have been most investigated for the development of several carrier systems intended for cancer diagnosis and therapy. Nonetheless, different and important delivery applications of the polysaccharide have also been described, including gene …
Predictability of drug encapsulation and release from propylene carbonate/PLGA microparticles.
2020
Abstract Key parameters for microparticle-based parenteral depot formulation development are entrapment efficiency and sustained drug release, which both depend on the intermolecular affinity of the components. Here, partial solubility parameters were evaluated as descriptors for 21 drug substances and 3 polymers in propylene carbonate (PC). Out of these 21 drug substances, eight BCS class II substances (celecoxib, clotrimazole, erythromycin, ibuprofen, indomethacin, itraconazole, lopinavir and ritonavir) were encapsulated using PLGA (Poly(DL-lactide-co-glycolide)) as polymer matrix and PC as a polar aprotic solvent in order to assign microparticle properties to potential affinity-related i…
Microparticle preparation by a propylene carbonate emulsification-extraction method
2018
Abstract The use of various harmful organic solvents for microparticle formulations is still widespread. Here, an alternative low toxicity solvent (propylene carbonate; PC) is proposed for the preparation of poly(lactic-co-glycolic-acid) (PLGA) microparticles. Based on the classical emulsification-solvent extraction methodology, the use of PC offers the unique advantage of an additional solvent extraction step using hydrolytic solvent cleavage during microparticle preparation. Spherical, rough-surfaced microparticles were obtained with a volume median diameter range from 20 to 60 µm. The residual PC content has been identified to be the major factor for the solidification hindrance, leading…
PLGA nanoparticles are effective to control the colonic release and absorption on ibuprofen.
2018
The oral controlled release (CR) formulations have become more important in recent years. Among them, the polymeric nanoparticles have been thoroughly studied during the last decades, consequently they are extensively employed for a broad range of applications and drugs. The objective of this research was to develop polymeric nanoparticles (NPs) of ibuprofen with poly(lactic-co-glycolic) acid (PLGA) as polymer, and to test their applicability for oral CR formulations development. Different proportions of drug/polymer were employed to develop the ibuprofen NPs and their in vitro release profiles were analysed. The in situ segmental permeability of ibuprofen was tested in Wistar rat and demon…