Device-related patient outcomes for coronary stents: A MAUDE database analysis.

The growing prevalence of coronary artery diseases in the US corresponds to the increasing use of minimally invasive techniques that require coronary stents. Although extensive research is available on the perioperative outcomes of the 3 stent options - bare-metal stents (BMS), drug-eluting stents (DES), and bioresorbable drug-eluting stents (BVS), a knowledge gap exists in the longitudinal monitoring of patient outcomes due to device-related causes. Therefore, our study examines the device-related patient outcome and the relative performance for BMS, DES, and BVS.

Hydrogel encapsulation to improve cell viability during syringe needle flow.

This work examines pluronic F-127 poloxamer for cell protection during injection through a syringe needle. Direct cell injection is a minimally invasive method for cell transplantation; however, it often results in poor cell viability. We proposed that encapsulating cells in this hydrogel would protect cells from detrimental mechanical forces during injection and increase cell viability.

Engineering the extracellular matrix for clinical applications: endoderm, mesoderm, and ectoderm.

Tissue engineering is rapidly progressing from a research-based discipline to clinical applications. Emerging technologies could be utilized to develop therapeutics for a wide range of diseases, but many are contingent on a cell scaffold that can produce proper tissue ultrastructure. The extracellular matrix, which a cell scaffold simulates, is not merely a foundation for tissue growth but a dynamic participant in cellular crosstalk and organ homeostasis.

Tissue scaffold surface patterning for clinical applications.

Patterned scaffold surfaces provide a platform for highly defined cellular interactions, and have recently taken precedence in tissue engineering. Despite advances in patterning techniques and improved tissue growth, no clinical studies have been conducted for implantation of patterned biomaterials. Four major clinical application fields where patterned materials hold great promise are antimicrobial surfaces, cardiac constructs, neurite outgrowth, and stem cell differentiation.

Advances in biomaterials for the treatment of intervertebral disc degeneration.

In the past decade, the number of treatment methods for disc degeneration has dramatically increased due to advances in biomaterials. Disc degeneration is one of the leading causes of lower back pain in the adult population, and a large percentage of patients seek surgical solutions. Therefore, there is a great clinical need for biomaterials to alleviate pain associated with disc degeneration.

Regulation of inflammatory and lipid metabolism genes by eicosapentaenoic acid-rich oil.

Omega-3-PUFAs, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), are associated with prevention of various aspects of metabolic syndrome. In the present studies, the effects of oil rich in EPA on gene expression and activation of nuclear receptors was examined and compared with other ω3-PUFAs. The EPA-rich oil (EO) altered the expression of FA metabolism genes in THP-1 cells, including stearoyl CoA desaturase (SCD) and FA desaturase-1 and -2 (FASDS1 and -2).

Pathway engineering strategies for production of beneficial carotenoids in microbial hosts.

Carotenoids, such as lycopene, β-carotene, zeaxanthin, canthaxanthin and astaxanthin have many benefits for human health. In addition to the functional role of carotenoids as vitamin A precursors, adequate consumption of carotenoids prevents the development of a variety of serious diseases. Biosynthesis of carotenoids is a complex process and it starts with the common isoprene precursors.

A disease-centered approach to biomaterials education and medical device design.

This paper describes the development of a novel elective course in biomaterials which integrates clinical medicine with engineering principles. In this educational approach, students are first introduced to disease pathologies and clinical needs, and then exposed to engineering technologies that can fulfill unmet needs. The course is directed toward the question, "Where are clinical needs most urgent, and how can engineering be applied to meet those needs?" This clinically-oriented, disease-centered approach is valuable for science and engineering education, as it relays to students the centrality of engineering in solving the world's most pressing healthcare problems.

Derivation and application of a mathematical model for long bone growth.

The objective of this work was to develop a mathematical model of long bone growth and to gain insights regarding growth disorders. A cell balance (mass balance of moving cells) assessment was performed on the three regions of the growth plate, to determine the variables (including number of proliferating cells, and division rate of proliferating cells) that influence tibia growth rate. Once this relationship was established, clinical data were used to understand how tibia growth rate and number of proliferating cells change with time.

Carbon nanobrush-containing poloxamer hydrogel composites for tissue regeneration.

The objective of this study was to examine potential uses for electrically conductive hydrogel composites in tissue engineering and tissue regeneration, and to explore the composites as a growth matrix for clinically relevant cell lines. The composite was comprised of carbon nanobrushes embedded in a biocompatible poloxamer gel. In this study, we assessed the ability of such composite gels to support the growth of fibroblasts and myocytes and eventually serve as a matrix to stimulate wound closure.

Metabolic engineering for the production of clinically important molecules: Omega-3 fatty acids, artemisinin, and taxol.

Driven by requirements for sustainability as well as affordability and efficiency, metabolic engineering of plants and microorganisms is increasingly being pursued to produce compounds for clinical applications. This review discusses three such examples of the clinical relevance of metabolic engineering: the production of omega-3 fatty acids for the prevention of cardiovascular disease; the biosynthesis of artemisinic acid, an anti-malarial drug precursor, for the treatment of malaria; and the production of the complex natural molecule taxol, an anti-cancer agent. In terms of omega-3 fatty acids, bioengineering of fatty acid metabolism by expressing desaturases and elongases, both in soybeans and oleaginous yeast, has resulted in commercial-scale production of these beneficial molecules.

Sealing and healing of clear corneal incisions with an improved dextran aldehyde-PEG amine tissue adhesive.

Purpose: To create a non-cytotoxic, spontaneously curing tissue adhesive that is strongly bonding and persistent enough that 1-2 μL is capable of sealing a clear corneal incision throughout the first five days of healing.

Methods: A novel prototype delivery device capable of delivering 1-2 μL of a two-component adhesive delivered aqueous solutions of dextran aldehyde and star PEG amine, which mixed by diffusion and crosslinked to form an adhesive hydrogel. Adhesive hydrogels were tested for rates of degradation in phosphate-buffered saline, leak pressures when used to seal clear corneal incisions in enucleated rabbit eyes, and in vitro cytotoxicity when placed in contact with NIH3T3 fibroblast cells.

Tissue engineering for clinical applications.

Tissue engineering is increasingly being recognized as a beneficial means for lessening the global disease burden. One strategy of tissue engineering is to replace lost tissues or organs with polymeric scaffolds that contain specialized populations of living cells, with the goal of regenerating tissues to restore normal function. Typical constructs for tissue engineering employ biocompatible and degradable polymers, along with organ-specific and tissue-specific cells.

Energetics of association in poly(lactic acid)-based hydrogels with crystalline and nanoparticle-polymer junctions.

We report the energetics of association in polymeric gels with two types of junction points: crystalline hydrophobic junctions and polymer-nanoparticle junctions. Time-temperature superposition (TTS) of small-amplitude oscillatory rheological measurements was used to probe crystalline poly(L-lactide) (PLLA)-based gels with and without added laponite nanoparticles. For associative polymer gels, the activation energy derived from the TTS shift factors is generally accepted as the associative strength or energy needed to break a junction point.

Poly(vinyl alcohol) acetoacetate-based tissue adhesives are non-cytotoxic and non-inflammatory.

Polymer-based tissue adhesives composed of poly(vinyl alcohol) acetoacetate (PVOH acac) and cross-linking amines were investigated for their effects on cell survival and inflammatory cell activation using in vitro mouse cell cultures. Cytotoxicity of tissue adhesives was evaluated by placing adhesives in direct contact with 3T3 fibroblast cells. Tissue adhesives formulated from PVOH acac and 3-aminopropyltrialkoxysilane (APS) were non-cytotoxic to fibroblasts; adhesives formulated from PVOH acac and aminated poly(vinyl alcohol) (PVOH amine) were also non-cytotoxic to fibroblasts.

Effect of pharmaceuticals on thermoreversible gelation of PEO-PPO-PEO copolymers.

Pluronic F127, a triblock copolymer of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), has generated considerable interest as a drug delivery vehicle due to its ability to gel at physiological temperatures. This work examines the gelation behavior of Pluronic F127 in the presence of a series of hydrophobic pharmaceuticals, to determine whether there is any correlation between gelation and physicochemical parameters of drug solutes. The study includes the local anesthetics dibucaine, lidocaine, and tetracaine; the pharmaceutical additives methyl paraben, ethyl paraben, and propyl paraben; the anti-cancer agents paclitaxel and baccatin III; and the anti-inflammatory agent sulindac.

Polysaccharide-based tissue adhesives for sealing corneal incisions.

Purpose: To investigate the ability of a novel polysaccharide-based tissue adhesive to seal corneal incisions, and to determine the effect of the tissue adhesive on corneal endothelial cells.

Methods: A polysaccharide-based tissue adhesive composed of dextran aldehyde and star PEG amines was applied to a 5-mm corneal incision on an enucleated rabbit eye, and the leak pressure of the eye was measured. The tissue adhesive was additionally incubated in direct contact with bovine corneal endothelial cells to evaluate cytotoxicity.

Biological characterization of Sorona polymer from corn-derived 1,3-propanediol.

The Sorona family of polymers, based on corn-derived 1,3-propanediol, have recently been developed as novel bio-based materials for use in plastics, films, and fibers. In the present study, Sorona polymers were investigated for their effects on cell survival and inflammatory cell activation using in vitro mouse cell cultures. Cytotoxicity of Sorona polymers was evaluated by placing material samples in direct contact with 3T3 fibroblast cells.

Correlation of visual in vitro cytotoxicity ratings of biomaterials with quantitative in vitro cell viability measurements.

Medical devices and implanted biomaterials are often assessed for biological reactivity using visual scores of cell-material interactions. In such testing, biomaterials are assigned cytotoxicity ratings based on visual evidence of morphological cellular changes, including cell lysis, rounding, spreading, and proliferation. For example, ISO 10993 cytotoxicity testing of medical devices allows the use of a visual grading scale.

Interactions of polysaccharide-based tissue adhesives with clinically relevant fibroblast and macrophage cell lines.

The effects of polysaccharide-based tissue adhesives on cell survival and inflammatory cell activation were determined using in vitro mouse cell cultures. Cytotoxicity of tissue adhesives was evaluated by placing adhesives in direct contact with 3T3 fibroblast cells. Polysaccharide-based tissue adhesives composed of dextran aldehyde and star PEG amine were non-cytotoxic to fibroblasts; in contrast, a commercial adhesive composed of 2-octyl cyanoacrylate was highly cytotoxic to fibroblasts.