Phase Separation at the Surface of Poly(ethylene oxide)-Containing Biodegradable Poly(<scp>l</scp>-lactic acid) Blends

Yu, Jinxiang; Mahoney, Christine M.; Fahey, A. J.; Hicks, Wesley L.; Hard, R; Bright, Frank V.; Gardella, Joseph A.

doi:10.1021/la901239v

Cited by 6 publications

(3 citation statements)

References 22 publications

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“…The calculated mesh sizes are of the same order of magnitude as the reported diameter of SDF-1α protein [4.4 nm (Huang, Shen et al 2003)]. Aside from the mesh size imposed on SDF-1α diffusion, hydrophilic and hydrophobic interactions with PEG and PLA domains, respectively, phase separation of the PLA and PEG domains (Yu, M. et al 2009), and inhomogeneity in the crosslinked network [i.e., microgel formation (Chi, Cai et al 2009)] can affect the release kinetics of SDF-1α from the PLEOF hydrogels.…”

Section: Discussionmentioning

confidence: 80%

Migration of marrow stromal cells in response to sustained release of stromal-derived factor-1α from poly(lactide ethylene oxide fumarate) hydrogels

Jabbari

2010

International Journal of Pharmaceutics

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Stromal derived factor-1α (SDF-1α) is an important chemokine in stem cell trafficking and plays a critical role in the homing of bone marrow stromal (BMS) cells. However, its use in tissue regeneration is limited by its relatively short half-life and the time-dependent nature of cell homing to the site of injury. The objective of this work was to investigate the release characteristics of SDF-1α from degradable poly (lactide ethylene oxide fumarate) (PLEOF) hydrogels and to determine the effect of sustained release of SDF-1α on migration of BMS cells. Three PLEOF hydrogels with poly(L-lactide) (PLA) fractions of 6, 9, and 24% by weight were synthesized. After the addition of chemokine, the polymerizing mixture was crosslinked to produce SDF-1α loaded PLEOF hydrogels. The hydrogels were characterized with respect to sol fraction, water uptake, degradation, SDF-1α loading efficiency and release kinetics, and migration rate of bone marrow stromal (BMS) cells. The more hydrophilic hydrogels with 6 and 9% PLA fraction had a pronounced burst release followed by a period of sustained release by diffusion for 21 days. The more hydrophobic hydrogel with 24% PLA fraction had a less pronounced burst release and displayed a slow but constant release by diffusion between days 1-9 followed by a fast release by diffusion-degradation from days 9 to 18. The fraction of active SDF-1α released from 6, 9, and 24% hydrogels after 21 days was 34.3, 32.3, and 35.8%, respectively. The migration of BMS cells in response to time-released SDF-1α closely followed the protein release kinetics from the hydrogels. The biodegradable PLEOF hydrogel may potentially be useful as a delivery matrix for sustained release of SDF-1α in the proliferative phase of healing for recruitment of progenitor cells in tissue engineering applications.

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Section: Discussionmentioning

confidence: 80%

Migration of marrow stromal cells in response to sustained release of stromal-derived factor-1α from poly(lactide ethylene oxide fumarate) hydrogels

Jabbari

2010

International Journal of Pharmaceutics

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“…The occurrence of micropores can be interpreted as follow. Because of the phase separation in PLLA/PEO blend (it has been discussed in detail in ref and ) and the existence of strong shear field during spin-coating or blade-coating, phase-separated PEO-rich phases are interconnected with each other. , They play the role of pore-forming agent upon water etching, creating the interpenetrated microchannels in the membranes. The successful removal of PEO by water etching can be validated by both weight calculation and differential scanning calorimetry (DSC) results (Figure S2).…”

mentioning

confidence: 99%

Micropore Geometry Manipulation by Macroscopic Deformation Based on Shape Memory Effect in Porous PLLA Membrane and its Enhanced Separation Performance

Zhao

Yang

Wang

et al. 2017

ACS Appl. Mater. Interfaces

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An effective strategy to tailor the microporous structures has been developed based on the shape memory effect in porous poly(l-lactic acid) membranes in which tiny crystals and amorphous matrix play the roles of shape-fixed phase and reversible-phase, respectively. Our results indicate that not only PLLA membranes but micropores exhibit shape memory properties. The proportional deformations on two scales have been achieved by uniaxial or biaxial tension, providing a facile way to manipulate continuously the size and the orientation degree of pores on microscale. The enhanced separation performance has been validated by taking polystyrene colloids with varying diameters as an example.

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“…In this study, we use poloxamer 188, which has an 1800 g/mol PPO midblock with a 3600 g/mol PEO block on each end. Poloxamers have been previously demonstrated to be miscible with PLA with a propensity to concentrate at the surface of PLA blends and impart wettability. − Studies have shown that interaction of the PPO block is more favorable with PLA relative to the PEO segments. , This leads to the PPO block embedding in the PLA matrix and coating the surface with hydrophilic PEO. Additionally, poloxamer is ideal for our application, as it has been shown to be biodegradable …”

Section: Introductionmentioning

confidence: 99%

Polylactide Foams with Tunable Mechanical Properties and Wettability using a Star Polymer Architecture and a Mixture of Surfactants

Dirlam

Goldfeld

Dykes

et al. 2018

ACS Sustainable Chem. Eng.

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Commercially available low-density, hydrophilic foams are principally produced from nonrenewable petrochemical feedstocks and suffer from challenging disposal avenues and effective recycling. We aim to develop a biodegradable alternative using materials from sustainable chemical feedstocks.Here we report the preparation of expanded poly(lactide) via carbon dioxide-mediated batch foaming under relatively mild conditions (6 MPa CO 2 , T ≤ 50 °C). By changing architecture, temperature, and surfactant loading, we obtain tunable densities from 0.05 to 0.3 g/cm 3 and compressive strengths from 1.2 to 0.05 MPa. The use of poly(lactide) with a multiarm star architecture is preferable over the linear analogue in preparing low-density foams. Polysorbate and poloxamer type surfactants were incorporated with 4-arm star poly(lactide) enabling further reduction in foam densities and imparting persistent wettability to inherently hydrophobic poly(lactide). The practical utility of these biodegradable poly(lactide) foams was demonstrated as a potential replacement for current phenolic resin-based foams.

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Phase Separation at the Surface of Poly(ethylene oxide)-Containing Biodegradable Poly(l-lactic acid) Blends

Cited by 6 publications

References 22 publications

Migration of marrow stromal cells in response to sustained release of stromal-derived factor-1α from poly(lactide ethylene oxide fumarate) hydrogels

Migration of marrow stromal cells in response to sustained release of stromal-derived factor-1α from poly(lactide ethylene oxide fumarate) hydrogels

Micropore Geometry Manipulation by Macroscopic Deformation Based on Shape Memory Effect in Porous PLLA Membrane and its Enhanced Separation Performance

Polylactide Foams with Tunable Mechanical Properties and Wettability using a Star Polymer Architecture and a Mixture of Surfactants

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