| 1. |
- Borzacchiello, A, et al.
(author)
-
Rheological characterization of vocal folds after injection augmentation in a preliminary animal study
- 2004
-
In: Journal of bioactive and compatible polymers (Print). - London : Sage Publications. - 0883-9115 .- 1530-8030. ; 19:4, s. 331-341
-
Journal article (peer-reviewed)abstract
- The investigation of vocal folds viscoelastic properties in an animal model (rabbit) after injection of various augmentation substances, 6 months after injection, is reported. The injected materials were: hyaluronan-based materials (Hylan B gel and Deflux(R)), cross-linked collagen (Zyplast(R)) and polytetrafluoroethylene (Teflon(R)). Rheological properties of the augmentation substances were also evaluated. The results from these animal experiments indicate that the viscoelastic properties of the vocal folds injected with Deflux(R), Zyplast(R) and Hylan B gel are similar to the healthy vocal folds (non-injected samples) used as control, thus demonstrating that these materials are good candidates for further studies aimed at restoring/preserving the vibratory capacity of the vocal folds with injection treatment in glottal insufficiency.
|
|
| 2. |
- Danmark, Staffan, et al.
(author)
-
Osteogenic Differentiation by Rat Bone Marrow Stromal Cells on Customized Biodegradable Polymer Scaffolds
- 2010
-
In: Journal of bioactive and compatible polymers (Print). - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 25:2, s. 207-223
-
Journal article (peer-reviewed)abstract
- In this report, poly(L-lactide-co-epsilon-caprolactone), poly(LLA-co-CL) and poly(L-lactide-co-1,5-dioxepan-2-one), poly(LLA-co-DXO) were evaluated and compared for potential use in bone tissue engineering constructs together with bone marrow stromal cells (BMSC). The copolymers were tailored to reduce the level of harmful tin residuals in the scaffolding. BMSC isolated from Sprague-Dawley rats were seeded onto the scaffolds and cultured in vitro for up to 21 days. Cell spreading and proliferation was analyzed after 72 h by scanning electron microscopy and thiazolyl blue tetrazolium bromide (MTT) conversion assay. Osteogenic differentiation of BMSC was evaluated by real-time PCR after 14 and 21 days of culture. Hydrophilicity was significantly different between poly(LLA-co-CL) and poly(LLA-co-DXO) with the latter being more hydrophilic. After 72 h, both scaffolds supported increased cell proliferation and the mRNA expression of osteocalcin and osteopontin was significantly increased after 21 days. Further investigation of these constructs, with lower levels of tin residuals, are being pursued.
|
|
| 3. |
- Edlund, Ulrica, et al.
(author)
-
A microspheric system : Hemicellulose-based hydrogels
- 2008
-
In: Journal of bioactive and compatible polymers (Print). - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 23:2, s. 171-186
-
Journal article (peer-reviewed)abstract
- Hydrogel microspheres were prepared from the major softwood hemicellulose polysaccharide acetylated galactoglucomannan. The dry and swollen morphology was assessed by scanning electron microscopy. The microspheres were loaded with either a small hydrophilic substance ( caffeine) or a macromolecular model protein ( bovine serum albumin) and afforded diffusion controlled release in vitro. Statistical multivariate analysis was used to systematically determine the influence and significance of the hydrogel composition, the crosslinking density, and the dimensions of the incorporated substance on the microsphere size and release rate.
|
|
| 4. |
- Edlund, Ulrica, et al.
(author)
-
Microspheres from poly(D,L-lactide)/poly(1,5-dioxepan-2-one) miscible blends for controlled drug delivery
- 2000
-
In: Journal of bioactive and compatible polymers (Print). - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 15:3, s. 214-229
-
Journal article (peer-reviewed)abstract
- Novel biodegradable microspheres were designed from blends of poly(D,L-lactide) (PDLLA) and poly(1,5-dioxepan-2-one) (PDXO). The addition of PDXO to PDLLA yielded a more pliable and versatile matrix, where the properties can be controlled by means of composition. The components were fully miscible and formed homogeneous, amorphous, smooth and dense microspheres. Blend composition was a vital factor in determining the blend properties, morphology and in vitro degradation. Diclofenac sodium, a non-steroidal anti-inflammatory drug, was incorporated into PDLLA-PDXO microspheres of various composition ratios. Sustained release of drug was obtained. The degradation and release rates of PDLLA-PDXO microspheres were dependent on the blend composition, providing a powerful means of controlling drug delivery.
|
|
| 5. |
- Guerzoni, Samuele, et al.
(author)
-
Combination of silica nanoparticles with hydroxyapatite reinforces poly (L-lactide acid) scaffolds without loss of bioactivity
- 2014
-
In: Journal of bioactive and compatible polymers (Print). - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 29:1, s. 15-31
-
Journal article (peer-reviewed)abstract
- Composite scaffolds of poly(l-lactide acid) and hydroxyapatite are of great interest in bone tissue engineering, but their mechanical properties are typically inferior to scaffolds of pure poly(l-lactide acid) due to agglomeration of the particles and weak interfacial component interaction. Fabrication strategies like double sonication of hydroxyapatite or increasing the amount of this inorganic filler do not effectively enhance the mechanical performance. In this study, poly(l-lactide acid) composites combining two types of fillers, mesoporous silica (SiO2) nanoparticles and hydroxyapatite, were developed to reinforce the poly(l-lactide acid) scaffold without any loss of bioactivity. A 5% addition of SiO2 nanoparticles to hydroxyapatite nanopowder and subjecting the scaffold formulation to double sonication increased the Young's modulus from 5 MPa (pure poly(l-lactide acid) scaffold) to almost 7 MPa (poly(l-lactide acid)/hydroxyapatite/SiO2 scaffold). In addition, the composite was able to deposit a layer of biomimetic hydroxyapatite both on the surface and interior of the scaffold after 21 days of immersion in a simulated body fluid. The manufacturing method was straightforward and economically viable and does not require any chemical modification of the particles' surfaces.
|
|
| 6. |
- Guzmán, Daniel, et al.
(author)
-
Preparation of hydrophilic poly(3-hydroxybutyrate) macroporous scaffolds through enzyme-mediated modifications
- 2011
-
In: Journal of Bioactive and Compatible Polymers. - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 26:5, s. 452-463
-
Journal article (peer-reviewed)abstract
- Scaffolds made from poly(3-hydroxybutyrate) were prepared by thermally induced phase separation from solutions in dioxane at temperatures above (23 degrees C) or below the freezing point of the solvent. At 23 degrees C, gelation occured with nano-fibrous network formation. The scaffolds prepared at -12 degrees C and -25 degrees C exhibited a highly porous morphology, with pores in the range of 3-25 mu m, caused by freezing of dioxane. The macroporous scaffolds, prepared at -12 degrees C, were treated with lipase to generate functional groups to which gelatin and glucosamine, respectively, were chemically coupled. The modified scaffolds had lower molecular weight, higher water content, lower melting temperature, and enthalpy. Cultivation of human embryonic fibroblasts on the macroporous scaffolds confirmed that the cells proliferated and adhered to the materials.
|
|
| 7. |
- Idris, Shaza B., et al.
(author)
-
Biocompatibility of Polyester Scaffolds with Fibroblasts and Osteoblast-like Cells for Bone Tissue Engineering
- 2010
-
In: Journal of bioactive and compatible polymers (Print). - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 25:6, s. 567-583
-
Journal article (peer-reviewed)abstract
- The aim of this study was to evaluate the in vitro cytotoxicity and cytocompatibility of the developed aliphatic polyester co-polymer scaffolds: poly(L-lactide-co-epsilon-caprolactone) and poly(L-lactide-co-1,5-dioxepan-2-one). The scaffolds were produced by solvent casting and particulate leaching, and tested by direct and indirect contact cytotoxicity assays on human osteoblast-like cells and mouse fibroblasts. Cell morphology was documented by light and scanning electron microscopy. Viability was assessed by the MTT, neutral red uptake, lactic dehydrogenase and apoptosis assays. Extraction tests confirmed that the scaffolds did not have a cytotoxic effect on the cells. The cells grew and spread well on the test scaffolds with good cellular attachment and viability. The scaffolds are noncytotoxic and biocompatible with the two cell types and warrant continued investigation as potential constructs for bone tissue engineering.
|
|
| 8. |
- Liu, Y., et al.
(author)
-
New biodegradable polymers from renewable sources - Segmented copolyesters of poly(1,3-propanediol succinate) and poly(ethylene glycol)
- 2002
-
In: Journal of bioactive and compatible polymers (Print). - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 17:3, s. 209-219
-
Journal article (peer-reviewed)abstract
- New high-molecular-weight hydrophobic/hydrophilic segmented copolymers of poly(ester-ether-carbonate) structure, containing poly(1,3-propylene succinate) (SP) and poly(ethylene glycol) (PEG) segments in the main chain, were synthesized and characterized. These copolymers were obtained by a two-step chain-extension reaction performed by the thermal polycondensation of alpha,omega-dihydroxy-oligo(1,3-propylene succinate) with PEG1000 and PEG2000, respectively. The molecular structure of all the synthesized materials was characterized by H-1-NMR, by SEC for molecular weights, and by DSC for thermal properties. The molecular characterizations were in agreement with the proposed structures. Solubility and swellability tests indicated that the introduction of hydrophilic PEG segments into the high molecular weight poly(1,3-propylene succinate)s imparted amphiphilic character to the new materials. This is expected to influence the biocompatibility and biodegradability of these materials. The new polymers, besides having a degradable backbone, were derived from the monomers, 1,3-propanediol and succinic acid, which are both obtainable from renewable sources. Therefore, they have a potential as environmental friendly materials.
|
|
| 9. |
- Mattioli-Belmonte, M, et al.
(author)
-
Suitable materials for soft tissue reconstruction : In vitro studies of cell-triblock copolymer interactions
- 2005
-
In: Journal of bioactive and compatible polymers (Print). - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 20:6, s. 509-526
-
Journal article (peer-reviewed)abstract
- Keratinocytes and fibroblasts have been grown onto a series of triblock copolymers based on 1,5-dioxepan-2-one (DXO) and L-lactide (LLA). The molar ratio of DXO and LLA were varied in the copolymers. This resulted in different degrees of hydrophilicity, which in turn influenced the cell growth. On these surfaces, the morphological appearance of the cells with their cell movements and growth were investigated by means of scanning electron microscopy, time-lapse videomicroscopy and immunohistochemistry. All results clearly showed that the keratinocytes and fibroblasts adhered best to the most hydrophilic copolymers. A majority of the keratinocytes seeded on the most hydrophilic copolymer also presented a polarized morphology indicating a migration tendency. The cell growth onto these materials are interesting since a possible application for these unique materials is as polymeric membranes for guided cutaneous and/or periodontal tissue generation.
|
|
| 10. |
- Schander, Kerstin, et al.
(author)
-
Response of Bone and Periodontal Ligament Cells to Biodegradable Polymer Scaffolds In Vitro
- 2010
-
In: Journal of bioactive and compatible polymers (Print). - : SAGE Publications. - 0883-9115 .- 1530-8030. ; 25:6, s. 584-602
-
Journal article (peer-reviewed)abstract
- In this in vitro study, the initial response of human periodontal ligament (PDL) cells and alveolar osteoblast-like cells (HOB) to three biodegradable polymers with varying pore size and different mechanical properties were evaluated. Scaffolds were synthesized from poly(L-lactide), [poly(LLA)], poly(L-lactide-co-1,5-dioxepan-2-one), [poly(LLA-co-DXO)], poly(L-lactide-co-epsilon-caprolactone), and [poly(LLA-co-CL)] with pore sizes greater or less than 90 mm by salt leaching. Cells were obtained from patients undergoing routine oral surgery. After 2-4 passages, the cells were grown on scaffolds and in culture plates (control) for 3 h (PDL cells), 3 days (PDL cells and HOB), 10 and 14 days (HOB), respectively. The cellular morphology and spreading were determined by scanning electron microscopy (SEM) and the attachment and proliferation were evaluated by MTT assays. The SEM images revealed heterogeneous cellular morphology and good spreading. Cellular attachment and proliferation were significantly higher on poly(LLA-co-DXO) and poly(LLA-co-CL) than on poly(LLA) scaffolds (p = 0.003) and highest for poly(LLA-co-DXO). Expression of bone formation markers, collagen-I (COL-I), transforming growth factor-beta(1) (TGF-beta(1)), and osteocalcin (OCN), was determined by ELISA. The expression of COL-1 was similar for HOB and PDL cells, but significantly higher for pore size >90 mm while the HOB expression of TGF-beta(1) and OCN was greater on poly(LLA-co-CL) and poly(LLA-co-DXO) than on poly(LLA) scaffolds.
|
|
