Preparation of polyurethane / poly (2-hydroxyethyl methacrylate) semi-IPNs containing cellulose nanocrystals for biomedical applications

A simple procedure has been developed to synthesize uncrosslinked soluble poly(hydroxyethyl methacrylate) (PHEMA) gels, ready for use in a subsequent fabrication stage. The presence of 75 wt % methanol (MetOH) or dimethylformamide (DMF) impedes lateral hydroxyl–hydroxyl hydrogen bonds between PHEMA macromers to form during their solution polymerization at 60 °C, up to 24 h. These gels remain soluble when properly stored in closed containers under cold conditions and, when needed, yield by solvent evaporation spontaneous physically-crosslinked PHEMA adapted to the mould used. Moreover, this two-step procedure allows obtaining multicomponent systems where a stable and water-affine PHEMA network would be of interest. In particular, amphiphilic polycaprolactone (PCL):PHEMA semi-interpenetrated (sIPN) substrates have been developed, from quaternary metastable solutions in chloroform (CHCl3):MetOH 3:1 wt. and PCL ranging from 50 to 90 wt % in the polymer fraction (thus determining the composition of the solution). The coexistence of these countered molecules, uniformly distributed at the nanoscale, has proven to enhance the number and interactions of serum protein adsorbed from the acellular medium as compared to the homopolymers, the sIPN containing 80 wt % PCL showing an outstanding development. In accordance to the quaternary diagram presented, this protocol can be adapted for the development of polymer substrates, coatings or scaffolds for biomedical applications, not relying upon phase separation, such as the electrospun mats here proposed herein (12 wt % polymer solutions were used for this purpose, with PCL ranging from 50% to 100% in the polymer fraction).

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Three-Dimensional Stable Alginate-Nanocellulose Gels for Biomedical Applications: Towards Tunable Mechanical Properties and Cell Growing

Nanomaterials ◽

10.3390/nano9010078 ◽

2019 ◽

Vol 9 (1) ◽

pp. 78 ◽

Cited By ~ 23

Author(s):

Priscila Siqueira ◽

Éder Siqueira ◽

Ana Elza De Lima ◽

Gilberto Siqueira ◽

Ana Delia Pinzón-Garcia ◽

...

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Tissue Engineering ◽

Wound Healing ◽

Cellulose Nanocrystals ◽

Biomedical Applications ◽

Cellulose Nanofibers ◽

Oxidized Cellulose ◽

Freeze Dried ◽

Alginate Gels

Hydrogels have been studied as promising materials in different biomedical applications such as cell culture in tissue engineering or in wound healing. In this work, we synthesized different nanocellulose-alginate hydrogels containing cellulose nanocrystals, TEMPO-oxidized cellulose nanocrystals (CNCTs), cellulose nanofibers or TEMPO-oxidized cellulose nanofibers (CNFTs). The hydrogels were freeze-dried and named as gels. The nanocelluloses and the gels were characterized by different techniques such as Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA), while the biological features were characterized by cytotoxicity and cell growth assays. The addition of CNCTs or CNFTs in alginate gels contributed to the formation of porous structure (diameter of pores in the range between 40 and 150 μm). TEMPO-oxidized cellulose nanofibers have proven to play a crucial role in improving the dimensional stability of the samples when compared to the pure alginate gels, mainly after a thermal post-treatment of these gels containing 50 wt % of CNFT, which significantly increased the Ca2+ crosslinking density in the gel structure. The morphological characteristics, the mechanical properties, and the non-cytotoxic behavior of the CNFT-alginate gels improved bioadhesion, growth, and proliferation of the cells onto the gels. Thus, the alginate-nanocellulose gels might find applications in tissue engineering field, as for instance, in tissue repair or wound healing applications.

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Temperature-responsive hydrogels containing new LCST methacrylate macromonomers

e-Polymers ◽

10.1515/epoly.2007.7.1.998 ◽

2007 ◽

Vol 7 (1) ◽

Author(s):

Anna Korytkowska-Wałach ◽

Anna Porwoł ◽

Mirosław Gibas

Keyword(s):

Phase Transition ◽

Biomedical Applications ◽

Tetraethylene Glycol ◽

Temperature Sensitive ◽

Hydroxyethyl Methacrylate ◽

Temperature Responsive ◽

Michael Type Addition ◽

Responsive Hydrogels ◽

Ether Ester ◽

Gel Transition

AbstractA series of hydrogels were synthesized: homopolymers of new temperature-sensitive methacrylate macromonomers of ether-ester structure, derived from monomethacrylate of tetraethylene glycol via Michael-type addition - oligo(TTEGMMA), and copolymers of oligo(TTEGMMA) with N-isopropylacrylamide (NIPAAm) or 2-hydroxyethyl methacrylate (HEMA). Hydrogels based on oligo(TTEGMMA) demonstrate broad volume phase transition. Combination of oligo(TTEGMMA) with NIPAAm or HEMA yielded hydrogels having narrower phase transition and lower gel transition temperature (LGTT) up to 43 °C at the most, which is in the range of interest for most biomedical applications.

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