RESUMO
Delignified wood (DW) offers a versatile platform for the manufacturing of composites, with material properties ranging from stiff to soft and flexible by preserving the preferential fiber directionality of natural wood through a structure-retaining production process. This study presents a facile method for fabricating anisotropic and mechanically tunable DW-hydrogel composites. These composites were produced by infiltrating delignified spruce wood with an aqueous gelatin solution followed by chemical crosslinking. The mechanical properties could be modulated across a broad strength and stiffness range (1.2-18.3 MPa and 170-1455 MPa, respectively) by varying the crosslinking time. The diffusion-led crosslinking further allowed to manufacture mechanically graded structures. The resulting uniaxial, tubular structure of the anisotropic DW-hydrogel composite enabled the alignment of murine fibroblasts in vitro, which could be utilized in future studies on potential applications in tissue engineering.
RESUMO
Polyelectrolyte multilayer coatings based on poly(methacrylic acid) and poly-l-histidine were formed on anodized titanium surfaces with adsorbed bone morphogenetic protein 2 (BMP-2) or basic fibroblast growth factor (FGFb). These coatings are proposed for use on titanium implanted devices. Coatings were capable of sustained release of growth factor over 25 days, with BMP-2 and FGFb exhibiting approximately identical release profiles. Cell culture on growth factor-eluting surfaces was more effective for preosteoblasts on BMP-2-eluting surfaces than for fibroblasts on FGFb-eluting surfaces. Cell counts at all time points on BMP-2-eluting surfaces were significantly higher than for those on anodized titanium or polyelectrolyte surfaces that did not contain BMP-2. Alkaline phosphatase levels were significantly higher after 21 days on BMP-2-eluting surfaces, indicating increased bone growth.
Assuntos
Proteína Morfogenética Óssea 2/farmacologia , Materiais Revestidos Biocompatíveis/química , Eletrólitos/química , Fator 2 de Crescimento de Fibroblastos/farmacologia , Histidina/química , Ácidos Polimetacrílicos/química , Próteses e Implantes , Adsorção , Fosfatase Alcalina/metabolismo , Animais , Contagem de Células , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fluoresceína-5-Isotiocianato/metabolismo , Humanos , Camundongos , Microscopia de Fluorescência , Células NIH 3T3 , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Técnicas de Microbalança de Cristal de Quartzo , TitânioRESUMO
Cells like sugar. General synthesis and potential of intracellular hydrophobic drug delivery of single-component polysaccharide capsules are pursued. The capsules can be generally assembled through hydrogen bonding networks but show striking shell robustness. The evidenced cell internalization, stimuli-responsiveness to local pH changes and high biocompatibilities of the capsules specifically favor their potential intracellular drug delivery.
Assuntos
Materiais Biocompatíveis/metabolismo , Cápsulas/metabolismo , Portadores de Fármacos/química , Preparações Farmacêuticas/metabolismo , Polissacarídeos/química , Sonicação , Animais , Materiais Biocompatíveis/química , Cápsulas/química , Quitosana/química , Fluoresceína-5-Isotiocianato/química , Fluoresceína-5-Isotiocianato/metabolismo , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Microscopia Confocal , Células NIH 3T3 , Preparações Farmacêuticas/química , Temperatura , Tolueno/químicaRESUMO
Polymer brushes on thiol-modified gold surfaces were synthesized by using terminal thiol groups for the surface-initiated free radical polymerization of methacrylic acid and dimethylaminoethyl methacrylate, respectively. Atomic force microscopy shows that the resulting poly(methacrylic acid) (PMAA) and poly(dimethylaminoethyl methacrylate) (PDMAEMA) brushes are homogeneous. Contact angle measurements show that the brushes are pH-responsive and can reversibly be protonated and deprotonated. Mineralization of the brushes with calcium phosphate at different pH yields homogeneously mineralized surfaces, and preosteoblastic cells proliferate on both the nonmineralized and mineralized surfaces. The number of living cells on the mineralized hybrid surfaces is ca. 3 times (PDMAEMA) and 10 times (PMAA) higher than on the corresponding nonmineralized brushes.
