Papers by Keyword: PLGA

Abstract: Aim:Doxorubicin-induced cardiotoxicity limited its clinical utilization in oncology. In this study, Dox was entrapped into PEG-PLGA Nanoparticles, cardiotoxicity of Dox or PEG-PLGA-Dox was investigated in rats. Materials and methods :PEG-PLGA-Dox was prepared via modified single emulsion method. Its characterization including size, Drug loading capacity (DLC), entrapment efficiency (EE) were estimated. The cardiotoxicity of PEG-PLGA-Dox was assessed on SD rats via echocardiography and biochemical indicators compare to free Dox and physical sodium. Results:The average diameter of PEG-PLGA-Dox is around 200 nm, with DLC about 10%.After administered PEG-PLGA-Dox, the ratio of heart weight to body weight decreased not as significant as Dox group, level of serum parameters and echocardiography parameter also decreased little compared to the Dox group. Conclusions:After entrapped into PEG-PLGA nanoparticle, Dox-induced cardiotoxicity was reduced significantly.

Abstract: Scaffold plays an important role in tissue engineering. In this study, porous PLGA scaffold was successfully prepared by mixed solvent systems using the thermally induced phase separation method. The PLGA scaffold shows fibrous matrix and interconnective pores, and the scaffold has high porosity and compressive modulus with dioxane/THF solvent system, which could be a very promising scaffold for tissue engineering.

Abstract: The last two decades have witnessed a plethora of novel biomaterials that work significantly in the discovery of drugs and the point check of drugs, Biosensors. PLGA (Poly-(L-Lactide-co-glycolic Acid)), has already been shown to be a substrate for manufacture of substrates for OFETs, that in the future would be the forefront of electroceuticals. But, Polylactic Acid (PLA) derived and pegylated nanoparticles generated scaffolds, promote neural self-differentiation, nanowires derived from Polythiophene (PTs) can be utilised in the area of biosensors. Similarly, PT derived PEDOT:PSS(poly (3,4-ethylenedioxythiophene) poly (styrenesulfonate) polymer doped with appropriate cations is useful to manipulate directly the biological response of cells on the same grounds, organic electrochemical transistors (OECTs) based on PEDOTPSS coupled with bilayer lipid membranes (BLMs) were shown to act as ion-to-electron converters. A solid-state ion bipolar junction transistor (IBJT) has been developed to serve as a circuit element for neurotransmitter signal delivery. Consequently, the traditional drug discovery methods have far gone by. This era demands a much more modified and multiple disciplined methods for modern drug discovery. This review gives an insight and instance of this paradigm.

Abstract: A systematic study on molecular structure of Poly (DL-lactide-co-glycolide) (PLGA) films by the methods of being chemically immobilized onto self-assembled monolayers (SAMs) and spin coating using Fourier transform infrared spectroscopy (FTIR), sum frequency generation (SFG) vibrational spectroscopy is reported. Especially, a surface sensitive second order nonlinear optical technique, SFG vibrational spectroscopy, was applied to study molecular structure on PLGA films. It is shown that the more chemical groups of PLGA thin films with being chemically immobilized have orientation than that of PLGA films made by spin coating on the basis of SFG vibrational spectroscopy data. The characterization of the other analytical techniques indicates similar results. This work will be an important step for future biomaterials design and understanding biosensors, biocompatibility and biomacromolecule (e.g. proteins and peptides) activity.

Abstract: In order to study in vitro release behavior of hydrophilic drugs in polymer nanofibers and establish a fast characterization method, tetracycline hydrochloride-loaded poly (lacticacid-co-glycolic acid) nanofiber mats with varied tetracycline hydrochloride contents and different lacticacid to glycolic ratios in PLGA were preparied by electrospinning. Accroding to Chinese Pharmacopoeia, a basic and an improved test devices and processes were compared and their validity were commented by using an UV-visible spectrophotometer method. Results showed that the improved method can be used to estimate in vitro drug release behavior of drug-loaded mats and the results was better than the basic method. When temperature affected cumulative release ratio under controlled error, flotation method can replace the centrifugation method during the first stage of drug release testing process. Parallel experiments were carried out and results indicated that nanofibres on different part of mats had a relative stable result and repeat experimental error was kept below 4%.

Abstract: The purpose of this research was to use mesoporous silicon (mpSi) as internal phase additive to improve the hydrophilic ofloxacin loaded by the hydrophobic PLGA materials through a double emulsion (water-in-oil-in-water) solvent extraction/evaporation method. Laser distribution analysis displayed low impact of MS additive on the final particles size. When compared to particle loading efficiency of none internal phase additives, MS internal phase group showed higher loading efficiency, and it increased with MS amounts inside the microparticles. All the burst releases of MS internal phase groups were severe than none MS group and was directly related the MS amount inside the microsphere. The release rate was increasing with the MS amounts added into the internal phase.

Abstract: Carbonate apatite (CO₃Ap) foam with interconnecting porous structure is a potential candidate as bone substitute material owing to its similarity to the cancellous bone with respect to composition, morphology and osteoclastic degradation. However, it is brittle and difficult to handle. This is thought to be caused by no organic material in the CO₃Ap foam. The aim of this study is to reinforce the CO₃Ap foam with poly (DL-lactide-co-glycolide) (PLGA). Immersion and vacuum infiltration methods were compared as reinforcing methods. Compressive strength of unreinforced CO₃Ap foam, (12.0 ± 4.9 kPa) increased after PLGA reinforcement by immersion (187.6 ± 57.6 kPa) or by vacuum infiltration (407 ± 111.4 kPa). Scanning electron microscopy (SEM) showed the preservation of full interconnecting porous structure of CO₃Ap foam after PLGA reinforcement using immersion or vacuum infiltration. Interface between the PLGA and CO₃Ap foam, however revealed that no gap was found between the PLGA and CO₃Ap foam interface when vacuum was used to reinforce the PLGA whereas a gap was found when simple immersion was used. Strong interface between PLGA and CO₃Ap foam is therefore thought to be the key for higher compressive strength. In conclusion, vacuum infiltration is a more efficient method to reinforce the CO₃Ap foam with PLGA for improving the mechanical strength without sacrificing the cancellous bone-type morphology.

Abstract: Periodontitis is one of the most common inflammatory diseases, which can lead to early tooth loss. The conventional treatment of periodontitis is to arrest the disease progression. Most reconstructive procedures involve application of bone substitutes, barrier membranes or a combination of both into the bony defects. Calcium phosphate cements (CPCs) are the predominant type of bone substitute material used for reasons of injectability and hence perfect filling potential for bone defects. Recently, injectable apatitic CPCs demonstrated to be more rapidly degradable when combined with poly (lactic-co-glycolic) acid (PLGA) microspheres. Further, PLGA microspheres can be used as a delivery vehicle for growth factors. In this study, the performance of injectable CPCs as a bone substitute material for alveolar bone defects created in Beagle dogs was evaluated. Four CPC-formulations were generated by incorporating hollow or dense PLGA microspheres, either or not loaded with the growth factors (platelet derived growth factor (PDGF) and insulin-like growth factor (IGF). Implantation period was 8 weeks. Bone formation was based on histological and histomorphometrical evaluation. The results demonstrated that filling alveolar bone defects with CPC-dense PLGA revealed significant more bone formation compared to CPC-hollow PLGA either or not loaded with IGF and PDGF. In summary, we conclude that injectable CPC-dense PLGA composites proved to be the most suitable material for a potential use as off the shelf material due to its good biocompatibility, enhanced degradability and subsequent bone formation.

Abstract: A novel merwinite/ Poly(lactic-co-glycolic) nanocomposite was synthesized by a solvent casting/salt leaching technique with varying merwinite contents from 10 to 30% (w/w). Poly(lactic-co-glycolic) /merwinite foams with a co-continuous structure of interconnected pores were formed. The microstructure of the pores and the walls was controlled by varying the merwinite content. The pore structure becomes more and more irregular with increasing merwinite content. Pore sizes ranging from several microns to a few hundred microns were obtained. The degradation assessment of the scaffolds is performed in phosphate-buffered saline (PBS) solution at 37°C. Weight loss during storage at 37°C in PBS (pH 7.4) was determined for the scaffolds. Weight loss increased from pure to high content during incubation time. The prepared merwinite/ (Polylactic-co-glycolic) nanocomposite with uniform microstructure may be used in bone tissue engineering applications.

Abstract: Hybrids of hydroxyapatite (HAp) and poly(L-lactic co glycolic) (PLGA) have been fabricated, which can be expected to be a novel filler for bone grafting. The porous HAp ceramics with bimodal pore structure have been fabricated from apatite fibers synthesized by homogeneous precipitation method. Then, HAp/PLGA hybrids have been fabricated by introducing PLGA having high molecular-weight into the open pores of the porous HAp ceramics. Total porosities of the porous HAp ceramics slightly decreased from 71.5% down to 67.4% after infiltrating PLGA into the porous HAp ceramics. The bending strength of the HAp/PLGA hybrids was ~ 8.3 MPa. The value attained about 2 times that of the porous HAp ceramics.