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Showing 1 to 20 of 54 for “"PLLA"”.
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Thermal and morphological analysis of collagen-plla electrospun blends
… occurring at the glass transition temperature of PLLA in the collagen-PLLA blended electrospun mats. It is speculated that occurrence of this thermal event is more prominent in PLLA with high molecular weight due to the presence of entanglements. It has also been demonstrated that electrospinning …
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Effects of Fused Filament Fabrication Process Variables on Microstructural Alignment and Intra-layer Properties in PLLA
… to produce thin, free-standing polylactic acid (PLLA) layers was developed to overcome the issue of first layer consistency. It was proposed that a sacrificial polyvinyl alcohol (PVA) layer might address issues associated with both damage during removal and print-to-print variability. To evaluate …
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Phase transitions of poly (l-lactic acid) in bulk and in solution
Poly(L-lactic acid) (PLLA) has been subject to intensive research in recent years because of its biodegradability. Applications of PLLA, such as porous tissue engineering scaffolds and excipients for controlled release, have been developed in the biomedical and pharmaceutical fields. The crystal …
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Poly(L-Lactic Acid) Langmuir Monolayers at the Air/Water Interface and Langmuir-Blodgett Films on Solid Substrates: Phase Behavior, Surface Morphology, and Crystallinity
… degree of crystallinity of poly(L-lactic acid) (PLLA) substrates have recently attracted considerable attention because of their applications in cell adhesion, tissue engineering, and drug delivery. Several techniques have been used to fabricate PLLA substrates, some of which may be invalid …
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Study of poly (l-lactic acid)/poly (d-lactic acid) stereocomplex as nucleating agent for poly (l- lactic acid) crystallization
… between optical isomers Poly (L-lactic acid) (PLLA) and Poly (D-lactic acid) (PDLA), provides improvements on PLA thermomechanical properties. To investigate the nucleating effect brought by the PLA stereocomplex, samples of PLLA blended with different content of PDLA are prepared by the …
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Mechanical properties of bio-absorbable materials
… The study focuses on Poly(l-lactic acid) (PLLA), Polyglycolic acid (PGA), Poly-e-caprolactone (PCL), matrices with Carbon fibers (AS4), Nylon fibers and PLLA fibers. Fiber coating effects have also been investigated, with compliant polymers (1%, 50% and 100% of matrix properties) and with …
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Electrospinning of biphasic biopolymer and polymer : a feasibility and characterization study
… The polymer of choice is Poly (1-lactic acid) (PLLA) combining with collagen. This approach has given fibers with diameter ranging from 650nm to over a micron. This method of electrospinning is the least successful due to the poor solvent miscibility and evaporation. The third approach to …
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Designing a safe dendronised polymeric nanocarrier for hydrophobic drugs or gene delivery in cancer therapy
… of hydrophobic drugs into liver cancer cells. G3(PLLA and OGPLLL) arginine dendron of third generation bearing eight peripheral hydrophobic or cationic groups (PBF and BOC or guanidine groups) were synthesised in high yield, identified and tested for purity using NMR, MS and TLC. A series of three …
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Effect of Laser Induced Crystallinity Modification on Degradation and Drug Release of Biodegradable Polymer
… polymers such as poly(L-lactic acid) (PLLA) are promising in drug delivery applications. In biodegradable polymer-based drug delivery systems, drugs are released at a rate determined by polymer degradation. Polymer degradation exhibits an undesirable induction period, during which a …
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Magnetic targeted drug delivery system in gene therapy
… transfection efficiency and low cytotoxicity. PLLA(poly(L lactic acid)) can be biodegradable and has high biocompatibility. PLLA is already used in functional biomedical materials, including functional gene vectors. This thesis covers the synthesis and characterization of superparamagnetic iron …
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Controlling the alignment and degradation of 3D printed poly-L-lactic acid for redesigned coronary stents
… of 3D printed single-layer poly-L-lactic acid (PLLA). Results showed that polymer chain alignment can be increased by raising the bed temperature, lowering the nozzle temperature or increasing nozzle diameter, with birefringence increasing from 0.0007 ± 0.0001 to 0.0011 ± 0.0003. In addition, …
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The Degradation and Drug Release Mechanisms of Poly(ethylene glycol)-functionalised Poly(L-lactide) Polymers
Poly(L-lactide) (PLLA) is a well-recognised bioresorbable polymer known to degrade after 1.5 to 5 years by hydrolysis. For certain medical device or drug delivery applications, it would be desirable to reduce this degradation time as strategies for tailoring degradation and drug release rates …
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Polymer based microscale and nanoscale technologies for optical and biomedical application
… method to make nanoscale patterns in PLLA films using replica-molding techniques. We produce very high fidelity replication of PLLA using double replication from master polycarbonate to PDMS mold and from PDMS mold to PLLA film by drop casting process. The surface characteristics of …
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Fundamental Studies of Various Poly(L-lactide)/clay Nanocomposite Systems by in-situ Polymerization
… using various montmorillonite organoclays (PLLA-MMT). When using tin (Il) 2-ethylhexanoate (Sn(Oct)2) as the catalyst, the reaction is believed to initiate from stannous alkoxides, formed from hydroxide (-OH) groups present in the reagents. Several quaternary ammoniums were ion-exchanged …
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Electro-mechanically interfacing with biology using piezoelectric polymer nanostructures
… bio-polymer poly-\textsc{l}-lactic acid (PLLA) have been fabricated, characterised and implemented in cell culture devices to investigate their potential for electromechanical stimulation of living tissue. Novel variations on the template-wetting method have been developed to create the …
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Investigation of electrospun fibrous scaffolds, locally delivered anti-inflammatory drugs, and neural stem cells for promoting nerve regeneration
… fibers composed of poly(L-lactic acid) (PLLA) and polycaprolactone (PCL) were prepared with and without the steroid anti-inflammatory drug, dexamethasone, encapsulated. Histological analysis of harvested subcutaneous implants demonstrated the PLLA fibers encapsulating dexamethasone …
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Fully-renewable and degradable thermoplastic elastomers.
… the amorphous PLA with semi-crystalline PLLA or PDLA significantly improved the strength of the material. Blends of the enantiomeric triblock copolymers further increased the strength through stereocomplexation of the enantiomeric polylactide segments. These results led to the …
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Fabrication of hydroxyapatite-biodegradable polymer scaffolds by electrospinning for potential bone tissue application
… polymers used are poly(L-lactic acid) (PLLA), and poly(lactide-co-glycolide) (PLGA). Two types of HA-polymer solutions are first prepared to achieve HA weight percentage of 0, 10, and 25%of the total combined weight of HA and PLLA, and HA and PLGA. The solutions are electrospun to form …
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The effect of nanostructuring and crystallinity on triboelectric energy harvesting devices for biomedical applications
… affinity into consideration, poly-L-lactic acid (PLLA) was chosen in this work as the tribopositive material, and polytetrafluroethylene (PTFE) and poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE)) as tribonegative materials. These materials were all nanostructured using a meltpress …
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