PDMSstar–PEG hydrogels prepared via solvent-induced phase separation (SIPS) and their potential utility as tissue engineering scaffolds

Abstract

Inorganic-organic hydrogels based on methacrylated star polydimethylsiloxane (PDMS(star)-MA) and diacrylated poly(ethylene glycol) (PEG-DA) macromers were prepared via solvent-induced phase separation (SIPS). The macromers were combined in a dichloromethane precursor solution and sequentially photopolymerized, dried and hydrated. The chemical and physical properties of the hydrogels were further tailored by varying the number average molecular weight (M(n)) of PEG-DA (M(n)=3.4k and 6k gmol(-1)) as well as the weight percent ratio of PDMS(star)-MA (M(n)=7k gmol(-1)) to PEG-DA from 0:100 to 20:80. Compared to analogous hydrogels fabricated from aqueous precursor solutions, SIPS produced hydrogels with a macroporous morphology, a more even distribution of PDMS(star)-MA, increased modulus and enhanced degradation rates. The morphology, swelling ratio, mechanical properties, bioactivity, non-specific protein adhesion, controlled introduction of cell adhesion, and cytocompatibility of the hydrogels were characterized. As a result of their tunable properties, this library of hydrogels is useful to study material-guided cell behavior and ultimate tissue regeneration.

Continuous gradient scaffolds for rapid screening of cell–material interactions and interfacial tissue regeneration

“…Consistent with that previously observed for single composition scaffolds (i.e. “non-gradients” not formed with a gradient maker), the PDMS star -MA formed discrete microspheres or was uniformly distributed when prepared from an DI-H 2 O[40] or DCM[35] precursor solution, respectively. This was attributed to the improved solubility of PDMS star -MA in DCM versus in DI-H 2 O.…”

“…This was attributed to the improved solubility of PDMS star -MA in DCM versus in DI-H 2 O. As also previously noted with non-gradient scaffolds[35], gradient scaffolds formed with a DCM precursor solution exhibited enhanced pore size, particularly in zones containing high levels of PDMS star -MA. The increased pore size is attributed to SIPS [35, 41].…”

“…In our previous work, introduction of inorganic, hydrophobic methacrylated star polydimethylsiloxane (PDMS star -MA) to PEG-DA hydrogels prepared with aqueous solvent broadened both chemical and physical properties [33]. Later, we demonstrated that both PEG-DA and PDMS star -PEG hydrogels could be prepared via solvent-induced phase separation (SIPS) by employing dichloromethane as an organic fabrication solvent followed by sequential solvent removal and hydration after curing [34–35]. SIPS produced hydrogels with low sol contents and low cytotoxicities as well as increased pore size, enhanced modulus and a more uniform distribution of PDMS star -MA versus analogous hydrogels fabricated from aqueous precursor solutions.…”

“…SIPS produced hydrogels with low sol contents and low cytotoxicities as well as increased pore size, enhanced modulus and a more uniform distribution of PDMS star -MA versus analogous hydrogels fabricated from aqueous precursor solutions. In addition, PDMS star -PEG hydrogels fabricated from aqueous precursor solutions were bioactive, forming hydroxyapatite when exposed to simulated body fluid (SBF)[35] and furthermore resulted in an increase in osteogenic differentiation of encapsulated mesenchymal stem cells (MSCs) in proportion to PDMS star -MA content [36]. Based on these properties, this hybrid PDMS star -PEG hydrogel scaffold system is particularly of interest for bone and osteochondral tissue engineering.…”

Synthesis of Polyvinyl Pirrolidone (PVC) /Κ-Carrageenan Hydrogel Prepared by Gamma Radiation Processing As a Function of Dose and PVP Concentration

“…Based on their physical properties that similar and compatible with human tissues, hydrogels have been studied extensively for biomedical applications. Particularly, they can be used as soft contact lenses [1][2][3], tissue engineering scaffolds [4][5][6][7], controlled drug-release vehicles [8][9][10][11] and wound dressings [12][13][14][15]. As wound dressing hydrogels have many advantages.…”