Biomedical subjects

Eugene D Boland

Publications and source records attributed to Eugene D Boland.

5 recordsLinked to original sources

PubMed2007

Electrospun fibrinogen: feasibility as a tissue engineering scaffold in a rat cell culture model.

Fibrinogen has a well-established tissue engineering track record because of its ability to induce improved cellular interaction and scaffold remodeling compared to synthetic scaffolds. While the feasibility of electrospinning fibrinogen scaffolds of submicron diameter fibers and their mechanical properties have been demonstrated, in vitro cellular interaction has not yet been evaluated. The goal of this study was to demonstrate, based on cellular interaction and scaffold remodeling, that electrospun fibrinogen can be used successfully as a tissue engineering scaffold. Electrospun fibrinogen scaffolds were disinfected, seeded with neonatal rat cardiac fibroblasts, and cultured for 2, 7, and 14 days. Cultures were treated to regulate scaffold degradation by either supplementing serum-containing media with aprotinin or crosslinking the scaffolds with glutaraldehyde vapor. Biocompatibility was assessed through a WST-1 cell proliferation assay. Postculture scaffolds were evaluated by scanning electron microscopy and histology. Cell culture demonstrated that fibroblasts readily migrate into and remodel electrospun fibrinogen scaffolds with deposition of native collagen. Supplementation of culture media with different concentrations of aprotinin-modulated scaffold degradation in a predictable fashion, but glutaraldehyde vapor fixation was less reliable. Based on the observed cellular interactions, there is tremendous potential for electrospun fibrinogen as a tissue engineering scaffold.

Animals↗

PubMed2005

Mechanical properties of electrospun fibrinogen structures.

Fibrin and fibrinogen have a well-established track record in tissue engineering due to their innate ability to induce improved cellular interaction and subsequent scaffold remodeling compared to synthetic scaffolds. Use of fibrinogen as a primary scaffold component, however, has been limited by traditional processing techniques that render scaffolds with insufficient mechanical properties. The goal of this study was to demonstrate, based on mechanical properties, that electrospun fibrinogen overcomes these limitations and can be successful as a tissue engineering scaffold or wound dressing. Electrospun fibrinogen scaffolds were characterized for fiber diameter and pore area and subsequently tested for uniaxial mechanical properties while dry and hydrated. In addition, uniaxial mechanical testing was conducted on scaffolds treated to regulate scaffold degradation in serum-containing media by supplementing the media with aprotinin or cross-linking the scaffolds with glutaraldehyde vapor. A linear relationship between electrospinning solution concentration and measured fiber diameter was seen; fiber diameters ranged from 120 to 610 nm over electrospinning concentrations of 80 to 140 mg/ml fibrinogen, respectively. Pore areas ranged from 1.3 microm(2) to 13 microm(2) over the same fibrinogen concentrations. Aprotinin in the culture media inhibited scaffold degradation in a predictable fashion, but glutaraldehyde vapor fixation produced less reliable results as evidenced by mechanical property testing. In conclusion, the mechanical characteristics of electrospun fibrinogen strongly support its potential use as a tissue engineering scaffold or wound dressing.

Animals↗

PubMed2005

Electrospinning polydioxanone for biomedical applications.

Polydioxanone (PDS) is a colorless, crystalline, bioabsorbable polymer that was first developed specifically for wound closure sutures. The compatibility, degradation rate, and mechanical properties (including shape memory) of PDS are of interest when considering the design of tissue engineering scaffolds. This research presents the electrospinning of PDS to fabricate unique nanofibrous structures for a variety of biomedical applications. Electrospinning is a polymer processing technique that utilizes an electric field to form fibers from a polymer solution or melt and allows the fabrication of nanofibrous non-woven structures. Results demonstrate the ability to control the fiber diameter of PDS as a function of solution concentrations and the fiber orientation with our prototype electrospinning apparatus. The results also show dependence between the fiber orientation and the elastic modulus, peak stress, and strain to failure of PDS in a uniaxial model.

Biocompatible Materials↗

PubMed2004

Utilizing acid pretreatment and electrospinning to improve biocompatibility of poly(glycolic acid) for tissue engineering.

Poly(glycolic acid) (PGA) has a long history as a bioresorbable polymer. Its biocompatibility is widely accepted, yet PGA is often rejected as a soft-tissue scaffold because of fibrous encapsulation. The goal of this study was to improve the soft-tissue biocompatibility of PGA by producing scaffolds composed of small-diameter fibers through electrospinning and subjecting these scaffolds to a concentrated hydrochloric acid (HCL) pretreatment. The theory is that small-diameter fibers will elicit a reduced immune response and HCl treatment will improve cellular interactions. Scaffolds were characterized in terms of fiber diameter and pore area via image-analysis software. Biocompatibility was assessed through a WST-1 cell-proliferation assay (in vitro) with the use of rat cardiac fibroblasts and rat intramuscular implantations (in vivo). Fibers produced ranged in diameter from 0.22 to 0.88 microm with pore areas from 1.84 to 13.22 microm(2). The untreated scaffold composed of 0.88-microm fibers was encapsulated in vivo and supported the lowest rates of cell proliferation. On the contrary, the acid pretreated scaffold with 0.22-microm fibers was incorporated into the surrounding tissue and exhibited proliferation rates that exceeded the control populations on tissue-culture plastic. In conclusion, this study has shown the ability to improve the biocompatibility of PGA through acid pretreatment of scaffolds comprised of submicron fiber diameters.

Animals↗

PubMed2004

Electrospinning collagen and elastin: preliminary vascular tissue engineering.

Significant challenges must be overcome before the true benefit and economic impact of vascular tissue engineering can be fully realized. Toward that end, we have pioneered the electrospinning of micro- and nano-fibrous scaffoldings from the natural polymers collagen and elastin and applied these to development of biomimicking vascular tissue engineered constructs. The vascular wall composition and structure is highly intricate and imparts unique biomechanical properties that challenge the development of a living tissue engineered vascular replacement that can withstand the high pressure and pulsatile environment of the bloodstream. The potential of the novel scaffold presented here for the development of a viable vascular prosthetic meets these stringent requirements in that it can replicate the complex architecture of the blood vessel wall. This replication potential creates an "ideal" environment for subsequent in vitro development of a vascular replacement. The research presented herein provides preliminary data toward the development of electrospun collagen and elastin tissue engineering scaffolds for the development of a three layer vascular construct.

Blood Vessel Prosthesis↗