Laponite nanoparticle-associated silated hydroxypropylmethyl cellulose as an injectable reinforced interpenetrating network hydrogel for cartilage tissue engineering.

Unlabelled: Articular cartilage is a connective tissue which does not spontaneously heal. To address this issue, biomaterial-assisted cell therapy has been researched with promising advances. The lack of strong mechanical properties is still a concern despite significant progress in three-dimensional scaffolds.

Interplay of thermal and covalent gelation of silanized hydroxypropyl methyl cellulose gels.

Silanized hydroxypropyl methyl cellulose (Si-HPMC) is a biocompatible polysaccharide that forms a covalently crosslinked hydrogel at all temperatures due to silanol condensation. Unmodified HPMC forms reversible turbid physical gels when heated above 55°C. The interaction between thermal gelation and covalent crosslinking of Si-HPMC was investigated with rheology, turbidity and microscopy.

Evidence for the coexistence of interpenetrating permanent and transient networks of hydroxypropyl methyl cellulose.

Dynamic mechanical properties of aqueous solutions of hydroxypropyl methyl cellulose (HPMC) were investigated using oscillatory shear measurements. The structure was investigated with light scattering. A systematic investigation of the frequency dependence of the shear moduli showed that HPMC forms two distinct interpenetrating networks.

Injection of calcium phosphate pastes: prediction of injection force and comparison with experiments.

Calcium phosphate ceramics suspensions (ICPCS) are used in bone and dental surgery as injectable bone substitutes. This ICPCS biomaterial associates biphasic calcium phosphate (BCP) granules with hydroxypropylmethylcellulose (HPMC) polymer. Different ICPCS were prepared and their rheological properties were evaluated in parallel disks geometry as a function of the BCP weight ratio (35, 40, 45 and 50 %).

The stability mechanisms of an injectable calcium phosphate ceramic suspension.

Calcium phosphate ceramics are widely used as bone substitutes in dentistry and orthopedic applications. For minimally invasive surgery an injectable calcium phosphate ceramic suspension (ICPCS) was developed. It consists in a biopolymer (hydroxypropylmethylcellulose: HPMC) as matrix and bioactive calcium phosphate ceramics (biphasic calcium phosphate: BCP) as fillers.

Kinetic studies of a composite carbon nanotube-hydrogel for tissue engineering by rheological methods.

Here we used rheological methods to study the gelation kinetics of silanized hydroxypropylmethylcellulose (HPMC-Si) hydrogel for tissue engineering. Firstly, the gelation time was determined from the independence of tan delta on frequency, and the Arrhenius law was applied to obtain the apparent activation energy of gelation, which was found to be about 109.0 kJ/mol.

Gelation studies of a cellulose-based biohydrogel: the influence of pH, temperature and sterilization.

The present paper investigates the rheological properties of silated hydroxypropylmethylcellulose (Si-HPMC) biohydrogel used for biomaterials and tissue engineering applications. The general property of this modified cellulose ether is the occurrence of self-hardening due to silanol condensation subsequent to a decrease in pH (from 12.4 to nearly 7.

The rheological properties of silated hydroxypropylmethylcellulose tissue engineering matrices.

This paper describes the rheological properties of silated hydroxypropylmethylcellulose (HPMC-Si) used in biomaterials domain as a three-dimensional synthetic matrix for tissue engineering. The HPMC-Si is an HPMC grafted with 3-glycidoxypropyltrimethoxysilane (GPTMS). HPMC and HPMC-Si were studied.

Revised state diagram of Laponite dispersions.

We propose a state diagram of charged disk-like mineral particle (Laponite) dispersions as a function of the Laponite concentration (C) and the concentration of added salt (C(s)), based on simple observation and light-scattering measurements. At low C or high C(s) the dispersions separate into two domains due to sedimentation of Laponite aggregates, while at high C and low C(s) they form homogeneous gels that do not flow upon tube reversal. The aggregation rate and the structure factor of the Laponite dispersions is determined with light scattering as a function of C and C(s).

Influence of pyrophosphate or polyethylene oxide on the aggregation and gelation of aqueous laponite dispersions.

The influence of pyrophosphate or polyethylene oxide (PEO) on the aggregation and gelation of dispersions of model disklike clay particles (Laponite) is studied using light scattering and rheology. Pyrophosphate adsorbs onto the positively charged rim and inhibits bond formation between the rim and the negatively charged faces of the particles. At low concentrations of pyrophosphate the aggregation of Laponite is only retarded, without significant modification of the structure of the aggregates and gels.