Additional file 2 of Computational modeling of phagocyte transmigration for foreign body responses to subcutaneous biomaterial implants in mice

Details of ordinary differential equation solution and synthetic data generation. (PDF 149 kb

Additional file 1 of Computational modeling of phagocyte transmigration for foreign body responses to subcutaneous biomaterial implants in mice

List of histamine, P selectin, PMN and M ÎŚ measurement data named. (XLS 31 kb

Phagocyte accumulation on the surfaces of PET disks implanted in volunteers with and without the treatment of H1 and H2 histamine receptor antagonists

<p><b>Copyright information:</b></p><p>Taken from "Histamine release and fibrinogen adsorption mediate acute inflammatory responses to biomaterial implants in humans"</p><p>http://www.translational-medicine.com/content/5/1/31</p><p>Journal of Translational Medicine 2007;5():31-31.</p><p>Published online 1 Jul 2007</p><p>PMCID:PMC1929055.</p><p></p> (A) Myeloperoxidase and non-specific esterase activities were measured to reflect the degree of accumulation of PMN and MØ, respectively. (B) The estimated numbers of adherent PMN, MØ, and total phagocytes (PMN+ MØ) are calculated. Vertical lines denote ± 1 Standard Deviation. Significance vs. control volunteers (without antagonists): * p < 0.05

Low-Initial-Modulus Biodegradable Polyurethane Elastomers for Soft Tissue Regeneration

The mechanical match between synthetic scaffold and host tissue remains challenging in tissue regeneration. The elastic soft tissues exhibit low initial moduli with a J-shaped tensile curve. Suitable synthetic polymer scaffolds require low initial modulus and elasticity. To achieve these requirements, random copolymers poly­(δ-valerolactone-<i>co</i>-ε-caprolactone) (PVCL) and hydrophilic poly­(ethylene glycol) (PEG) were combined into a triblock copolymer, PVCL–PEG–PVCL, which was used as a soft segment to synthesize a family of biodegradable elastomeric polyurethanes (PU) with low initial moduli. The triblock copolymers were varied in chemical components, molecular weights, and hydrophilicities. The mechanical properties of polyurethanes in dry and wet states can be tuned by altering the molecular weights and hydrophilicities of the soft segments. Increasing the length of either PVCL or PEG in the soft segments reduced initial moduli of the polyurethane films and scaffolds in dry and wet states. The polymer films are found to have good cell compatibility and to support fibroblast growth in vitro. Selected polyurethanes were processed into porous scaffolds by a thermally induced phase-separation technique. The scaffold from PU–PEG_1K–PVCL_6K had an initial modulus of 0.60 ± 0.14 MPa, which is comparable with the initial modulus of human myocardium (0.02–0.50 MPa). In vivo mouse subcutaneous implantation of the porous scaffolds showed minimal chronic inflammatory response and intensive cell infiltration, which indicated good tissue compatibility of the scaffolds. Biodegradable polyurethane elastomers with low initial modulus and good biocompatibility and processability would be an attractive alternative scaffold material for soft tissue regeneration, especially for heart muscle

Triggerable Degradation of Polyurethanes for Tissue Engineering Applications

Tissue engineered and bioactive scaffolds with different degradation rates are required for the regeneration of diverse tissues/organs. To optimize tissue regeneration in different tissues, it is desirable that the degradation rate of scaffolds can be manipulated to comply with various stages of tissue regeneration. Unfortunately, the degradation of most degradable polymers relies solely on passive controlled degradation mechanisms. To overcome this challenge, we report a new family of reduction-sensitive biodegradable elastomeric polyurethanes containing various amounts of disulfide bonds (PU-SS), in which degradation can be initiated and accelerated with the supplement of a biological product: antioxidant-glutathione (GSH). The polyurethanes can be processed into films and electrospun fibrous scaffolds. Synthesized materials exhibited robust mechanical properties and high elasticity. Accelerated degradation of the materials was observed in the presence of GSH, and the rate of such degradation depends on the amount of disulfide present in the polymer backbone. The polymers and their degradation products exhibited no apparent cell toxicity while the electrospun scaffolds supported fibroblast growth <i>in vitro</i>. The <i>in vivo</i> subcutaneous implantation model showed that the polymers prompt minimal inflammatory responses, and as anticipated, the polymer with the higher disulfide bond amount had faster degradation <i>in vivo</i>. This new family of polyurethanes offers tremendous potential for directed scaffold degradation to promote maximal tissue regeneration

The accumulation of CD11b+ inflammatory cells in the trabecular meshwork.

<p>The representative immunohistochemically stained images showed the accumulation of CD11b+ inflammatory cells (labeled green; DAPI staining to locate cell nucleus) in the trabecular meshwork following particle injection (A). The extent of CD11b+ cell accumulation in the trabecular meshwork was quantified (B). Data are mean ± standard deviation. Significance of PLLA, PS, HA, PNIPAM vs. BSS control; * p<0.05 Correlation between CD11b+ inflammatory cells and average IOP changes in different test groups was also determined (C).</p

Evaluation of retinal tissue morphology following intravitreal injection.

<p>Representative H&E stained retinal tissues were shown here (A). The thickness of the retinal tissue was also calculated and then compared (B). Data are mean ± standard deviation. Significance of PLLA, PS, HA, PNIPAM vs. BSS control; * p<0.05.</p

Distribution of FITC-labeled PNIPAM nanoparticles after intravitreous administration over a day.

<p>Localization of fluorescence in the posterior segments of the eye at various time points (2, 4 and 24 hours) was observed (A) and quantified (B). Quantification of the normalized fluorescence intensity at various locations (TB: Trabecular Meshwork; RA: Retina; ON: Optic Nerve) at various time points (C).</p

Multipotent MSCs exist in Balb/c mice peritoneal effluents.

<p>(A) Peritoneal cell population from animals with 2 day implants. (B) Recruitment of inflammatory cells and MSCs in mice peritoneal cavity after catheter implantation. (C) Expression of surface markers on peritoneal MSCs. (D) Peritoneal cells differentiated into specific lineages appropriate conditions. Morphology of undifferentiated cells is compared with cells differentiating into specific lineages like osteogenic (Alizarin Red S stain), adipogenic (Oil Red O stain), myogenic (α-smooth muscle actin) and neurogenic (NF-M and Class III β-tubulin stain). (Mag 200×, scale bar 100 µm, statistical significance of cell numbers at various time points tested using One Way ANOVA, *p<0.05).</p

Histological assessment of corneal and iris tissue after intravitreous implantation.

<p>The representative H&E images of the cornea (A) and iris (B) tissue were shown here. Based on H&E staining images, the influence of particle property on the thickness of the corneal (C) and iris (D) thickness were quantified. Data are mean ± standard deviation. Significance of PLLA, PS, HA, PNIPAM vs. BSS control; * p<0.05.</p