Search results for "Poly(lactic acid)"

New gellan gum-graft-poly(D,L-lactide-co-glycolide) copolymers as promising bioinks: Synthesis and characterization

2020

This research focused on the aim of tackling the urgent demand of printable biomaterials, hence we synthetized and characterized three gellan gum-graft-poly(d,l-lactide-co-glycolide) copolymers (GGm-PLGA a, b and c) which differed in the graft substitution degree. We investigated the effect of the polyester chain grafted onto hydrophilic backbone of gellan gum in terms of physicochemical properties and the ability of the system to print 3D cell laden constructs. In particular, we evaluated thermo-rheological, ionotropic crosslinking, shear thinning, swelling and stability properties of these copolymers and their derived biomaterials and findings related to the degree of functionalization. M…

Blending PLLA with PLA so as to tune the biodegradabilty of polymeric scaffolds for soft tissue engineering

2008

Characterization and biodistribution of Au nanoparticles loaded in PLGA nanocarriers using an original encapsulation process

2021

Due to their imaging and radiosensitizing properties, ultrasmall gadolinium chelate-coated gold nanoparticles (AuNP) represent a promising approach in the diagnosis and the treatment of tumors. However, their poor pharmacokinetic profile, especially their rapid renal clearance prevents from an efficient exploitation of their potential for medical applications. The present study focuses on a strategy which resides in the encapsulation of AuNP in large polymeric NP to avoid the glomerular filtration and then to prolong the vascular residence time. An original encapsulation procedure using the polyethyleneimine (PEI) was set up to electrostatically entrap AuNP in biodegradable poly(lactic-co-g…

Immunohistochemical and morphological characteristics of tissues response to polylactic acid membranes with silver nanoparticles

2019

Background The aim of this research was to study anti-microbial and anti-inflammatory characteristics of silver nanoparticles helping bone structures to recover during late stage of parodontitis, which afterwards will increase the effect of bone regeneration operations. Material and Methods We assessed colloid solution-derived silver nanoparticles coating of polylactic acid membrane regarding tissue foreign body response. Thirty eight polylactic acid membranes were implanted intracranially in rabbits – ten unmodified (control group) and twenty eight with silver nanoparticles coating (experimental group). In controls, penicillin was used for infection prophylaxis. Tissue response was assesse…

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…

Model predictive control for continuous lactide ring‐opening polymerization processes

2020

International audience; Polylactic acid (PLA) is an attractive environment-friendly thermoplastic that is bio-sourced and biodegradable. PLA is industrially produced by the ring-opening polymerization of Lactide. This reaction is sensitive to drifts in the operating conditions and impurities in the raw materials that may affect the reaction rate as well as the polymer properties, which can be very costly in continuous processes. It is therefore crucial to employ a control strategy that allows recovering the nominal conditions and maintaining the desired properties and conversion level in case of drift. Three control strategies are discussed in this paper: Proportional-Integral controller (P…

Bilayer biodegradable films prepared by co-extrusion film blowing: Mechanical performance, release kinetics of an antimicrobial agent and hydrolytic …

2020

Abstract Bilayer biodegradable, eco-friendly films were prepared by co-extrusion film blowing, coupling polylactic acid (PLA) and Bio-flex ® (BIO). Furthermore, in the PLA layer, carvacrol (CRV) was added as a natural antimicrobial additive, whereas a nanoclay (D72T) was integrated to protect CRV from volatilization and to modulate release. The materials were analyzed by morphological, chemical-physical, mechanical testing. Furthermore, CRV release and degradation tests were performed. The results pointed out that coupling the two matrices allows gathering the stiffness of PLA with the ductility of BIO. Furthermore, the interlayer adhesion is promoted by CRV. D72T exerts a key-role in avoid…

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 …

POLYASPARTAMIDE-POLYLACTIDE GRAFT COPOLYMERS WITH TUNABLE PROPERTIES FOR THE REALIZATION OF FLUORESCENT NANOPARTICLES FOR IMAGING

2015

Here, the synthesis and the characterization of novel amphiphilic graft copolymers with tunable properties, useful in obtaining polymeric fluorescent nanoparticles for application in imaging, are described. These copolymers are obtained by chemical conjugation of rhodamine B (RhB) moieties, polylactic acid (PLA), and O-(2-aminoethyl)-O'-methyl poly(ethylene glycol) (PEG) on α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA). In particular, PHEA is first functionalized with RhB to obtain PHEA-RhB with a derivatization degree in RhB (DDRhB ) equal to 0.55 mol%. By varying the reaction conditions, different amounts of PLA are grafted on PHEA-RhB to obtain PHEA-RhB-PLA with DDPLA equal to 1.9, 4…