Surface Modification of PLGA Electrospun Scaffolds for Wound Healing and Drug Delivery Applications
Year: 2008
Type: article
Abstract: PLGA scaffolds used for wound healing and drug delivery can be surface modified to control cellular attachment to the fibers.An in situ technique has been developed whereupon surface modifying polymers migrate to PLGA microfiber surfaces during electrospinning processes by thermally induced phase separation.Biodegradable scaffolds capable of blocking or encouraging cellular adhesions have been fabricated.An electrospun scaffold is proposed in which a primary scaffold facilitates enhanced cellular attachment, while a secondary scaffold, that blocks cellular interactions, is intended to carry a drug payload to aid in tissue development.Thus, PLGA is surface modified by blending with collagen (I), fibronectin, PEG-grafted-chitosan, and PEG-PLGA block copolymer.Physical characterization of the surface-modified PLGA scaffolds is performed to define the shape, fiber diameter, and surface texture of the electrospun fibers.Additionally, assessment of contact angle and mechanical strength are examined to distinguish wettability and tensile characteristics, respectively.Biological characterization is performed to assess cellular adhesion characteristics, to examine the cellular preference between two different surface-modified blends in a single scaffold, and for the probing of vinculin proteins constituting focal adhesion sites to determine cellular adhesion mechanisms.Results indicate that electrospinning produces textured surface-modified microfibers not significantly different from pure PLGA fiber scaffolds.Contact angle results indicate that surface modification alters surface hydrophilicity.iv Tensile testing determines that surface modifications do not alter yield or tensile strength, but have an effect on the elastic modulus.Results of cellular adhesion studies indicate that the addition of collagen promotes cellular binding, but is not significantly greater than the control.Cellular adhesion among competitive pairings of the modified blends shows no significant differences.Probing of vinculin proteins is inconclusive.Conclusions based upon the physical and biological characterizations indicate that the TIPS technique used for surface modification of PLGA is an ineffective technique, although collagen (I) and PEG-grafted-chitosan may represent the most efficacious biomaterials for use as surface modifiers of PLGA scaffolds.v DEDICATION I would like to dedicate this thesis to my mother, Mary Anne Ricci, for her passion and zest for life, which have shaped this author's character and personality.Her willingness to support my quest of higher education and the understanding of the hardships associated with the journey are deserving of the highest honors and gratitude.I love you Mom.Thank you.Additionally, I would also like to dedicate this work to my former mentor, Dr.Charles G. Orosz , who was an extraordinary man, as well as the foremost immunologist in his field.Known simply as CGO, he succumbed to a rare immunological disease at just 56 years young, which left his family, friends and colleagues in a state of shock and loss.CGO is sorely missed today, but will always be remembered by this author for the impact he had on my life as an ambitious researcher.He commanded an infectious admiration, and I cherish the opportunity to have been his friend.
Author: Jacob A. Iselin
Institution: University of Akron
Language: English
Subfield: Biomaterials
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2598180539