Poly(lactic acid) blends in biomedical applications

Saini, Prabhjot; Arora, Meenakshi; Kumar, M. N. V. Ravi

doi:10.1016/j.addr.2016.06.014

Cited by 436 publications

(279 citation statements)

References 158 publications

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“…A full cycle of the shape-memory procedure consists of three stages of material shape: original shape, temporary shape and original shape recovery. Because of the good mechanical strength, biocompatibility and the SME, PLA has good application prospects in many biomedical fields such as vascular stent, drug release, thrombus removal, surgical suture and tissue engineering scaffolds [12,13,14]. Stack et al [15] implanted biodegradable Poly- l -Lactic Acid (PLLA) scaffolds into experimental dogs.…”

Section: Introductionmentioning

confidence: 99%

Radial Compressive Property and the Proof-of-Concept Study for Realizing Self-expansion of 3D Printing Polylactic Acid Vascular Stents with Negative Poisson’s Ratio Structure

Zhao

et al. 2018

Materials

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Biodegradable stents offer the potential to reduce the in-stent restenosis by providing support long enough for the vessel to heal. The polylactic acid (PLA) vascular stents with negative Poisson’s ratio (NPR) structure were manufactured by fused deposition modeling (FDM) 3D printing in this study. The effects of stent diameter, wall thickness and geometric parameters of arrowhead NPR structure on radial compressive property of 3D-printed PLA vascular stent were studied. The results showed that the decrease of stent diameter, the increase of wall thickness and the increase of the surface coverage could enhance the radial force (per unit length) of PLA stent. The radial and longitudinal size of PLA stent with NPR structure decreased simultaneously when the stent was crimped under deformation temperature. The PLA stent could expand in both radial and longitudinal direction under recovery temperature. When the deformation temperature and recovery temperature were both 65 °C, the diameter recovery ratio of stent was more than 95% and the maximum could reach 98%. The length recovery ratio was above 97%. This indicated the feasibility of utilizing the shape memory effect (SME) of PLA to realize the expansion of 3D-printed PLA vascular stent under temperature excitation.

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Section: Introductionmentioning

confidence: 99%

Radial Compressive Property and the Proof-of-Concept Study for Realizing Self-expansion of 3D Printing Polylactic Acid Vascular Stents with Negative Poisson’s Ratio Structure

Zhao

et al. 2018

Materials

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“…It is a promising alternative to many petroleum-based commodity plastics and entered the market of medical applications. 8,[15][16][17] Despite its many positive features, its poor mechanical properties as a pure homopolymer have to be overcome by blending with additives and other polymers. 18 Copolymerization, either randomly or in the form of BCPs, is another option to modify the properties of PLA.…”

Section: Introductionmentioning

confidence: 99%

“…From a material point of view, miscibility of polymers provides the opportunity to create properties unavailable in the individual one-component systems. 8 Through mixing, the thermal, mechanical, rheological, crystallization and degradation properties can be tuned according to the requirements. [9][10][11][12][13][14] Understanding and controlling the structural evolution through a variable temperature range is essential for the application of the materials.…”

Section: Introductionmentioning

confidence: 99%

“…18 Copolymerization, either randomly or in the form of BCPs, is another option to modify the properties of PLA. 8,19,20 PLA is produced by ring-opening polymerization (ROP) of lactide (LA), the cyclic diester of lactic acid, which contains two chiral centers and thus exists as three stereoisomers (L-LA, D-LA and DL-LA). Polymers of DL-LA are amorphous.…”

Section: Introductionmentioning

confidence: 99%

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Inversion of crystallization rates in miscible block copolymers of poly(lactide)-block-poly(2-isopropyl-2-oxazoline)

et al. 2018

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a Miscible block copolymers (BCPs) are rarely studied. When one or both components of such BCPs are semi-crystalline polymers, strong effects on the crystallization behavior can be expected. We present a study of 18 miscible BCPs comprised of poly(lactide) (PLLA, semi-crystalline and PDLLA, amorphous) and poly(2-isopropyl-2-oxazoline) (PiPOx, semi-crystalline) with PiPOx volume fractions of 0.14 < ϕ PiPOx < 0.82. All BCPs exhibit a single glass transition and form a homogeneous melt. Mixing has a plasticizing effect on PiPOx and increases its crystallization rates (DSC). In contrast, the crystallization rates of PLLA are dramatically reduced, or in most cases entirely prevented. During isothermal crystallization at 130°C, the crystallization rates of the BCPs were inverted in comparison with those of the parent homopolymers. Crystallization drives the BCPs to phase separate and the formed crystalline structure is that of the parent homopolymers. The fast crystallization of PiPOx confines the observed superstructure. The BCPs were studied on multiple length scales -from the atomic level (WAXS, IR spectroscopy) to the meso level (AFM, SAXS) and the macroscopic superstructure ( polarized optical microscopy). A mechanism of the structure evolution is presented.

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“…However, carving TCP at the operational site in order to yield distinctly shaped scaffolds for contour reconstruction is still below state of the art [12]. Seeking better alternatives, we chose to employ poly-L-lactic acid (PLLA) and poly- ε -caprolactone (PCL), abbreviated in this contribution to PLLA-b-PCL polymer (PbP), particularly due to its known biocompatibility [13, 14]). The PbP which was used in this study (Fig.…”

Section: Introductionmentioning

confidence: 99%

Hard Tissue Augmentation of Aged Bone by Means of a Tin-Free PLLA-PCL Co-Polymer Exhibiting in vivo Anergy and Long-Term Structural Stability

et al. 2019

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Background: Due to aging, tissue regeneration gradually declines. Contemporary strategies to promote tissue-specific regeneration, in particular in elderly patients, often include synthetic material apt for implantation primarily aiming at upholding body functions and regaining appropriate anatomical and functional integrity. Objective: Biomaterials suitable for complex reconstruction surgical procedures have to exert high physicochemical stability and biocompatibility. Method: A polymer made of poly-L-lactic acid and poly-ε-caprolactone was synthesized by means of a novel tin-free catalytic process. The material was tested in a bioreactor-assisted perfusion culture and implanted in a sheep model for lateral augmentation of the mandible. Histological and volumetric evaluation was performed 3 and 6 months post-implantation. Results: After synthesis the material could be further refined by cryogrinding and sintering, thus yielding differently porous scaffolds that exhibited a firm and stable appearance. In perfusion culture, no disintegration was observed for extended periods of up to 7 weeks, while mesenchymal stromal cells readily attached to the material, steadily proliferated, and deposited extracellular calcium. The material was tested in vivo together with autologous bone marrow-derived stromal cells. Up to 6 months post-implantation, the material hardly changed in shape with composition also refraining from foreign body reactions. Conclusion: Given the long-term shape stability in vivo, featuring imperceptible degradation and little scarring as well as exerting good compatibility to cells and surrounding tissues, this novel biomaterial is suitable as a space filler in large anatomical defects.

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Poly(lactic acid) blends in biomedical applications

Cited by 436 publications

References 158 publications

Radial Compressive Property and the Proof-of-Concept Study for Realizing Self-expansion of 3D Printing Polylactic Acid Vascular Stents with Negative Poisson’s Ratio Structure

Radial Compressive Property and the Proof-of-Concept Study for Realizing Self-expansion of 3D Printing Polylactic Acid Vascular Stents with Negative Poisson’s Ratio Structure

Inversion of crystallization rates in miscible block copolymers of poly(lactide)-block-poly(2-isopropyl-2-oxazoline)

Hard Tissue Augmentation of Aged Bone by Means of a Tin-Free PLLA-PCL Co-Polymer Exhibiting in vivo Anergy and Long-Term Structural Stability

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