A Novel Hybrid-Structured Titanium Surface Promotes Adhesion of Human Dermal Fibroblasts and Osteogenesis of Human Mesenchymal Stem Cells while Reducing S-epidermidis Biofilm Accumulation
differentiation; energy; hydrophilicity; implants; in-vitro; Materials Science; nanotopography; osseointegration; osteoactivin; osteoblast lineage cells; responses
We provide a comparative analysis of protein adsorption, primary human cell behavior, and biofilm formation on modified titanium substrates of either micro-, nano-, or hybrid micro/nano-scale feature sizes. While studies revealed that nano-scale structures initially decreased the attachment and spreading of both human fibroblasts (hDFs) and mesenchymal stem cells (hMSCs), hMSC differentiation studies revealed that hybrid structures promoted the highest levels of osteogenic gene expression and attenuated biofilm formation by Staphylococcus epidermidis. Taken together, this novel approach of generating a hybrid topographical feature results in a potential implant material capable of enhanced dermal cell adhesion and osteogenic differentiation while limiting biofilm accumulation.
Park B W; Krieger J; Sondag G R; Moussa F M; Rankenberg J; Safadi F F; Gatsonis N A; McGimpsey W G; Lambert C R; Malcuit C
Advanced Engineering Materials
2016
2016-04
Journal Article
<a href="http://doi.org/10.1002/adem.201500282" target="_blank" rel="noreferrer noopener">10.1002/adem.201500282</a>
Amphiphilic networks .10. Diffusion of glucose and insulin (and nondiffusion of albumin) through amphiphilic membranes
cells; Drug Release; Engineering; Materials Science; pancreas; sequential co-polymers; telechelic polymers; transfer agents inifers
Select semipermeable amphiphilic membranes have been prepared and their diffusional characteristics for glucose, insulin, and albumin investigated. The membranes were prepared by cast copolymerization of a hydrophilic monomer (i.e., N,N-dimethyl acrylamide, or N,N-dimethylaminoethyl methacrylate) with the hydrophobic crosslinker methacrylate-ditelechelic polyisobutylene. The products have sufficient mechanical properties for the fabrication of swollen membranes, sheets, tubes, etc. Membranes have been identified which allowed the rapid simultaneous countercurrent diffusion of glucose (M-n = 180 Da) and insulin (M-n = 5733 Da) but did not allow albumin (Mn similar to 60,000 Da) to pass. Evidently, the effective molecular weight cutoff point of these membranes is in the 6-60-KDa range. (C) 1997 John Wiley & Sons, Inc.
Shamlou S; Kennedy J P; Levy R P
Journal of Biomedical Materials Research
1997
1997-05
Journal Article
<a href="http://doi.org/10.1002/(sici)1097-4636(199705)35:2%3C157::aid-jbm3%3E3.0.co;2-m" target="_blank" rel="noreferrer noopener">10.1002/(sici)1097-4636(199705)35:2%3C157::aid-jbm3%3E3.0.co;2-m</a>
Lyotropic chromonic liquid crystals for biological sensing applications
biosensor; cells; Chemistry; chromonics; Crystallography; ligand-receptor binding; liquid crystal; Materials Science
We describe director distortions in the nematic liquid crystal (LC) caused by a spherical particle with tangential surface orientation of the director and show that light transmittance through the distorted region is a steep function of the particle's size. The effect allows us to propose a real-time microbial sensor based on a lyotropic chromonic LC (LCLC) that detects and amplifies the presence of immune complexes. A cassette is filled with LCLC, antibody, and antigen-bearing particles. Small and isolated particles cause no macroscopic distortions of the uniformly aligned LCLC. Upon antibody-antigen binding, the growing immune complexes.
Shiyanovskii S V; Lavrentovich O D; Schneider T; Ishikawa T; Smalyukh I I; Woolverton C J; Niehaus G D; Doane K J
Molecular Crystals and Liquid Crystals
2005
2005
Journal Article
<a href="http://doi.org/10.1080/15421400590957288" target="_blank" rel="noreferrer noopener">10.1080/15421400590957288</a>
Infusion of iodine-based contrast agents into poly(p-dioxanone) as a radiopaque resorbable IVC filter
degradation; Engineering; in-vivo; Materials Science; release; triclosan; vena-cava filters
To determine the feasibility of infusing resorbable inferior vena cava (IVC) filter with iodine-based contrast agents to produce a radiopaque, computed tomography (CT)-visible IVC filter. Infused poly(p-dioxanone) (PPDO) was obtained by incubating PPDO in different concentrations of 4-iodobenzoyl chloride (IBC) and 2,3,5-triiodobenzoic acid (TIBA). Characterizations of infused and nascent PPDO were done using elemental analysis, micro-CT, tensile strength analysis, scanning electron microscopy, and differential scanning calorimetry. Elemental analysis showed percentage loading of 1.07 +/- 0.08 for IBC and 0.73 +/- 0.01 for TIBA. The iodine loading remained the same within 2 weeks for TIBA but decreased to about 80 % with IBC when subjected to physiological conditions. Micro-CT images showed increased attenuation of the infused PPDO compared with the nascent PPDO. The Hounsfield unit values for infused and nascent sutures were 110 +/- 40 and 153 +/- 53 for PPDO infused with 2 mg/mL IBC and TIBA, respectively, but only 11.35 +/- 2 for nascent PPDO. In contrast the HU for bone was 116 +/- 37. Tensile strength analysis showed maximum loads of 1.01 +/- 0.43 kg and 10.02 +/- 0.54 kg for IBC and TIBA, respectively, and 10.10 +/- 0.64 kg for nascent PPDO. Scanning electron microscopy showed that the morphology of the PPDO surface did not change after coating and preliminary cytotoxicity assay showed no killing effect on Hela cells. PPDO infused with a contrast agent is significantly more radiopaque than nascent PPDO on micro-CT imaging. This radiopacity could allow the position and integrity of infused resorbable IVC filter to be monitored while it is in place, thus increasing its safety and efficacy as a medical device.
Singhana B; Chen A; Slattery P; Yazdi I K; Qiao Y; Tasciotti E; Wallace M; Huang S; Eggers M; Melancon M P
Journal of Materials Science-Materials in Medicine
2015
2015-03
Journal Article
<a href="http://doi.org/10.1007/s10856-015-5460-0" target="_blank" rel="noreferrer noopener">10.1007/s10856-015-5460-0</a>
Dextran-Peptide Hybrid for Efficient Gene Delivery
cationic lipids; cells; Chemistry; cytotoxicity; drug delivery; in-vitro; Materials Science; nanoparticles; nonviral vector; plasmid dna; polyethylenimine; therapy
Gene therapy has drawn significant interest in the past two decades since it provides a promising strategy to treat both genetic disorders and acquired diseases. However, the transfer of gene therapy to clinical applications is troubled with many difficulties, since many current systems are of toxicity, low transfection efficiency and low biodegradability. To address these challenges, we developed a dextran-peptide hybrid system as a safe and efficient vector for gene therapy and investigated the structure-function-cytotoxicity relationship of this dextran-peptide hybrid system. Dextrans (Dex10, Dex20, and Dex70) with different molecular weights (10, 20 and 70 kDa) were conjugated with a cationic peptide, R5H5, at various degrees of substitution. Gene expression and cytotoxicity mediated by this delivery system were evaluated against SKOV-3 human ovarian carcinoma cells and compared to 25 kDa branched poly(ethylenimine) (PEI). The results showed that Dex10-R5H5 and Dex20-R5H5 hybrids derived from low molecular weight dextrans induced higher gene expression and lower cytotoxicity than Dex70-R5H5 hybrid from higher molecular weight dextran. The best performance on gene expression was achieved by Dex10-R5H5 at 40% substitution of R5H5, which induced greater gene expression than PEI at a low N/P ratio of S. Dex10-R5H5/DNA complexes at 40% substitution of R5H5 also showed much higher cell viability (93%) than PEI/DNA (66%) at the same N/P ratio. These results indicate that the Dex-R5H5 hybrid with the low molecular weight of dextran and the high degree of substitution of R5H5 is a very promising material for safe and efficient gene therapy.
Tang Q; Cao B; Lei X; Sun B B; Zhang Y Q; Cheng G
Langmuir
2014
2014-05
Journal Article
<a href="http://doi.org/10.1021/la500905z" target="_blank" rel="noreferrer noopener">10.1021/la500905z</a>
Engineering Alkoxyphenacyl-Polycarbonate Nanoparticles for Potential Application in Near-Infrared Light-Modulated Drug Delivery via Photon Up-Conversion Process
800 nm; alkoxylphenacyl-based polycarbonates; biocompatibility; Chemistry; Doxorubicin; Drug Release; luminescence; Materials Science; mesoporous-silica; nanocrystals; Nanotechnology; Near-Infrared Light; photodynamic therapy; Physics; release; Science & Technology - Other Topics; Stimuli-Responsive; upconverting nanoparticles; uv
Photoresponsive delivery systems that are activated by high energy photo-triggers have been accorded much attention because of the capability to achieve reliable photoreactions at short irradiation times. However, the application of a high energy photo-trigger (UV light) is not clinically viable. Meanwhile, the process of photon-upconversion is an effective strategy to generate a high energy photo-trigger (in-situ) through exposure to clinically relevant near-infrared (NIR) light. In this regard, we synthesized photon upconverting nanocrystals (UCNCs) that were subsequently loaded into photoresponsive nanoparticles (NPs) that were prepared using alkoxyphenacyl-based polycarbonate homopolymer (UCNC-APP-NPs). UCNC loading affected resultant NP size, size distribution, colloidal stability but not the zeta potential. The efficiency of NIR-modulated drug delivery was impacted by the heterogenetic nature of the resultant UCNC-APP-NPs which was plausibly formed through a combination of UCNC entrapment within the polymeric NP matrix and nucleation of polymer coating on the surface of the UCNCs. The biocompatibility of UCNC-APP-NPs was demonstrated through cytotoxicity, macrophage activation, and red blood cell lysis assays. Studies in tumor-bearing (nu/nu) athymic mice showed a negligible distribution of UCNC-APP-NPs to reticuloendothelial tissues. Further, distribution of UCNC-APP-NPs to various tissues was in the order (highest to lowest): Lungs> Tumor > Kidneys > Liver > Spleen> Brain > Blood > Heart. In all, the work highlighted some important factors that may influence the effectiveness, reproducibility and biocompatibility of drug delivery systems that operate on the process of photon-upconversion.
Wehrung D; Chamsaz E A; Andrews J H; Joy A; Oyewumi M O
Journal of Nanoscience and Nanotechnology
2017
2017-07
Journal Article
<a href="http://doi.org/10.1166/jnn.2017.13449" target="_blank" rel="noreferrer noopener">10.1166/jnn.2017.13449</a>
2.5d Constructs For Characterizing Phase Separated Polymer Blend Surface Morphology In Tissue Engineering Scaffolds
2; 3d; 5D scaffolds; cell-shape; differentiation; Engineering; L-lactide); Materials Science; mechanical-properties; poly(D; poly(e-caprolactone); polymer blends; porosity; proliferation; topography
Marszalek J E; Simon C G; Thodeti C; Adapala R K; Murthy A; Karim A
Journal of Biomedical Materials Research Part A
2013
2013-05
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1002/jbm.a.34439" target="_blank" rel="noreferrer noopener">10.1002/jbm.a.34439</a>
Affinity Manipulation Of Surface-conjugated Rgd Peptide To Modulate Binding Of Liposomes To Activated Platelets
cyclic RGD; delivery systems; drug-eluting stents; Engineering; insight; integrin alpha(iib)beta(3); liposomes; Materials Science; nanoparticles; peptide modification; platelet-targeting; responses; restenosis; therapy
Platelet adhesion, activation and fibrinogen-mediated aggregation are primary events in vascular thrombosis and occlusion. An injectable delivery system that can carry thrombolytics selectively to the sites of active platelet aggregation has immense potential in minimally invasive targeted therapy of vascular occlusion. To this end we are studying liposomes surface-modified by fibrinogen-mimetic RGD motifs that can selectively target and bind integrin GPIIb-IIIa on activated platelets. Here we report liposome surface-modification with a conformationally constrained high affinity cyclic RGD motif to modulate the GPIIb-IIIa-binding capability of the liposomes. Such affinity enhancement is important for practical in vivo applications to compete with native fibrinogen towards binding GPIIb-IIIa. The platelet-binding of RGD-modified liposomes was studied by fluorescence and scanning electron microscopy, and flow cytometry, in vitro. Binding of RGD-modified liposomes was also tested in vivo in a rat carotid injury model and analyzed ex vivo by fluorescence microscopy. The results from all experiments show that cyclic RGD-liposomes bind activated platelets significantly higher compared to linear RGD-liposomes. Hence, the results establish the feasibility of modulating the platelet-targeting and binding ability of vascularly targeted liposomes by manipulating the affinity of surface-modifying ligands. (c) 2008 Elsevier Ltd. All rights reserved.
Huang G F; Zhou Z M; Srinivasan R; Penn M S; Kottke-Marchant K; Marchant R E; Gupta A S
Biomaterials
2008
2008-04
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/j.biomaterials.2007.12.015" target="_blank" rel="noreferrer noopener">10.1016/j.biomaterials.2007.12.015</a>
Characterization And Performance Of Membranes Designed For Macroencapsulation/implantation Of Pancreatic Islet Cells
amphiphilic networks; amphiphilic polymer membranes; Engineering; glucose challenge; macroencapsulation of pancreatic islets; macroencapsulatory membranes; Materials Science; oxygen permeability; polyisobutylene; rat; stars
Amphiphilic polymer membranes were synthesized for macroencapsulation of cells and characterized by select chemical and biological techniques. The membranes were prepared by crosslinking hydrophilic poly(N,N-dimethyl acrylamide) (PDMAAm) main chains with hydrophobic di-, tri-, and octa-methacrylate telechelic polyisobutylene (PIB) stars. The hydrophilic/hydrophobic composition and the molecular weights between crosslink sites (both M-c,M-hydrophilic and M-c,M-hydrophobic) were controlled by synthesis conditions. Small tubular membranes were made by in situ rotational copolymerization/crosslinking and filled with pancreatic rat islets. The water-swelling behavior, mechanical properties, and oxygen and insulin diffusion were studied. Macroencapsulatory performance of these membranes was investigated in vitro by macroencapsulation of pancreatic rat islets within tubular membranes for up to 1.5 months, and studying the insulin secreting ability of encapsulated islets in culture. The membranes are robust and maintain their integrity for the period of encapsulation. They allow oxygen and insulin diffusion. Macroencapsulated islets maintained their viability and insulin secretion over an extended period (i.e., 45 days). (C) 2003 Elsevier Science Ltd. All rights reserved.
Isayeva I S; Kasibhatla B T; Rosenthal K S; Kennedy J P
Biomaterials
2003
2003-09
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/s0142-9612(03)00172-8" target="_blank" rel="noreferrer noopener">10.1016/s0142-9612(03)00172-8</a>
Synthesis, Permeability And Biocompatibility Of Tricomponent Membranes Containing Polyethylene Glycol, Polydimethylsiloxane And Polypentamethylcyclopentasiloxane Domains
biocompatibility; compatibility; delivery; Engineering; hydrogels; insulin diffusion; Materials Science; membrane; molecular weight cut-off; networks; oxygen diffusion; star; surface-properties; water
The synthesis of "smart" tricomponent amphiphilic membranes containing poly(ethylene glycol) (PEG), polydimethylsiloxane (PDMS) and polypentamethylcyclopentasiloxane (PD(5)) domains is described. Contact angle hysteresis indicates that in air, the surfaces of such PEG/PD(5)/PDMS membranes are enriched by the hydrophobic components, PDMS and PD(5), while in water, the surfaces are rich in the hydrophilic PEG. The oxygen permeability of a series of membranes with varying M(c,hydrophilic) (M(n,PEG) = 4600, 10,000 and 20,000 g/mol) and varying PEG/PD(5)/PDMS compositions was studied. Oxygen permeability increased with the amount of PDMS in the membrane. The molecular weight cut-off (MWCO) ranges and permeability coefficients of insulin through a series of PEG/PD(5)/PDMS(=29/14/57) membranes with varying M(c,hydrophilic) were determined. Insulin permeability is directly related to Mc,hydrophilic of the membrane. MWCO studies show that the membranes are semipermeable to, i.e., allow the transport of smaller proteins such as insulin (M(n) = 5733 g/mol, R(s) = 1.34 nm) and cytochrome c (M(n) = 12,400 g/mol, R(s) = 1.63 nm), but are barriers to larger proteins such as albumin (M(n) = 66,000 g/mol, R(s) = 3.62 nm). Implantation of representative membranes in rats showed them to be biocompatible. According to these studies, PEG/PD(5)/PDMS membranes may be suitable for biological applications, e.g., immunoisolation of cells. (C) 2003 Elsevier Science Ltd. All rights reserved.
Kurian P; Kasibhatla B; Daum J; Burns C A; Moosa M; Rosenthal K S; Kennedy J P
Biomaterials
2003
2003-09
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/s0142-9612(03)00189-3" target="_blank" rel="noreferrer noopener">10.1016/s0142-9612(03)00189-3</a>
Collagen As A Scaffold For Biomimetic Mineralization Of Vertebrate Tissues
3 dimensions; bone; Chemistry; elastic energy-storage; electron-microscopic tomography; fibril structure; i collagen; Materials Science; matrix; mechanical-properties; molecular packing; organic; turkey tendons
Collagen is a well known protein component that has the capacity to mineralize in a variety of vertebrate tissues. In its mineralized form, collagen potentially can be utilized as a biomimetic material for a variety of applications, including, for example, the augmentation and repair of damaged, congenitally defective, diseased or otherwise impaired calcified tissues such as bone and cartilage. In order to effect an optimal response in this regard, the manner in which collagen becomes mineralized is critically important to understand. This paper provides details concerning collagen-mineral interaction and its implications with respect to designing biomimetic mineralizing collagen that will be functionally competent in its biological, chemical, and biomechanical properties.
Landis W J; Silver F H; Freeman J W
Journal of Materials Chemistry
2006
2006
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1039/b505706j" target="_blank" rel="noreferrer noopener">10.1039/b505706j</a>
New Biomaterial As A Promising Alternative To Silicone Breast Implants
arborescent; biocompatibility; Biopolymers; block-copolymers; Breast implants; elastomers; Engineering; Histological study; in-vivo; Materials Science; mechanical-properties; polyisobutylene-based biomaterials; polystyrene; prostheses; rupture; SIBS; thermoplastic; women
One in eight American women develops breast cancer. Of the many patients requiring mastectomy yearly as a consequence, most elect some form of breast reconstruction. Since 2006, only silicone breast implants have been approved by the FDA for the public use. Unfortunately, over one-third of women with these implants experience complications as a result of tissue-material biocompatibility issues, which may include capsular contracture, calcification, hematoma, necrosis and implant rupture. Our group has been working on developing alternatives to silicone. Linear triblock poly(styrene-b-isobutylene-b-styrene) (SIBS) polymers are self-assembling nanostructured thermoplastic rubbers, already in clinical practice as drug eluting stent coatings. New generations with a branched (arborescent or dendritic) polyisobutylene core show promising potential as a biomaterial alternative to silicone rubber. The purpose of this pre-clinical research was to evaluate the material-tissue interactions of a new arborescent block copolymer (TPE1) in a rabbit implantation model compared to a linear SIBS (SIBSTAR 103T) and silicone rubber. This study is the first to compare the molecular weight and molecular weight distribution, tensile properties and histological evaluation of arborescent SIBS-type materials with silicone rubber before implantation and after explantation. (C) 2013 Elsevier Ltd. All rights reserved.
Lim G T; Valente S A; Hart-Spicer C R; Evancho-Chapman M M; Puskas J E; Horne W I; Schmidt S P
Journal of the Mechanical Behavior of Biomedical Materials
2013
2013-05
Journal Article or Conference Abstract Publication
<a href="http://doi.org/10.1016/j.jmbbm.2013.01.025" target="_blank" rel="noreferrer noopener">10.1016/j.jmbbm.2013.01.025</a>