Search results for "PLGA"
showing 10 items of 31 documents
Fabrication of amorphous strontium polyphosphate microparticles that induce mineralization of bone cells in vitro and in vivo.
2017
Abstract Here we describe the fabrication process of amorphous strontium-polyphosphate microparticles (“Sr-a-polyP-MP”). The effects of these particles on growth and gene expression were investigated with SaOS-2 cells as well as with human mesenchymal stem cells (MSC) and compared with those particles prepared of amorphous calcium-polyphosphate (“Ca-a-polyP-MP”) and of strontium salt. The results revealed a markedly higher stimulation of growth of MSC by “Sr-a-polyP-MP” compared to “Ca-a-polyP-MP” and a significant increase in mineralization of SaOS-2 cells, as well as an enhanced upregulation of the expression of the genes encoding for alkaline phosphatase and the bone morphogenetic protei…
Polyphosphate as a Bioactive and Biodegradable Implant Material: Induction of Bone Regeneration in Rats
2016
Inorganic polyphosphate (polyP) is a naturally occurring polymer that is bioresorbable and anabolically active on bone forming cells in vitro. In order to demonstrate if polyP also shows morphogenetic activity in vivo, animal studies are performed applying the rat calvarial defect model. Poly(D,L-lactide-co-glycolide) (PLGA) microspheres with a narrow size distribution (≈820 μm) are prepared, containing either encapsulated polyP or β-tricalcium phosphate (β-TCP), used as a reference material. Discs are prepared from the microspheres and inserted into 10 mm large defects created in the calvaria of rats. Both the formation of COL-I and the expression of ALP is upregulated, as well as the exte…
Folate-targeted supramolecular vesicular aggregates as a new frontier for effective anticancer treatment in in vivo model.
2012
Abstract Supramolecular vesicular aggregates (SVAs), made up by self-assembling liposomes and polyasparthydrazide co-polymers conjugated to folic acid molecules were extensively investigated in this manuscript as potential active targeting formulation for anticancer drug delivery. Folate-targeted systems (FT-SVAs) were used to treat breast cancer and to further proof the potential in vivo administration of these systems for the therapeutic treatment for several aggressive solid tumors. The physicochemical and technological parameters of FT-SVAs are suitable for their potential in vivo administration. The chemotherapeutic activity of GEM-loaded FT-SVAs was increased during in vivo experiment…
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…
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…
Performance of polyester-based electrospun scaffolds under in vitro hydrolytic conditions: From short-term to long-term applications
2019
The evaluation of the performance of polyesters under in vitro physiologic conditions is essential to design scaffolds with an adequate lifespan for a given application. In this line, the degradation-durability patterns of poly(lactide-co-glycolide) (PLGA), polydioxanone (PDO), polycaprolactone (PCL) and polyhydroxybutyrate (PHB) scaffolds were monitored and compared giving, as a result, a basis for the specific design of scaffolds from short-term to long-term applications. For this purpose, they were immersed in ultra-pure water and phosphate buffer solution (PBS) at 37 °
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…
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…