Publications in January and February 2013

At the beginning of year 2013 numerous articles about chitosan and chitosan derivatives were published.  All in all 286 publications were released in January and February by leading scientists from China (86 articles), USA (25) and India (25).  The main research field addresses chitosan in animal and human studies, nanoparticles and pharmaceutical preparations.

Table: Journals publishing the highest number of chitosan-related articles in January and February 2013.
Source: GoPubMed

Chitosan and some of its derivatives possess high medical potential as scaffolds in the field of tissue engineering. Two exciting publications are presented below, which introduce novel chitosan modifications and their valuable properties for tissue engineering.

Fluorescent labelling of chitosan for use in non-invasive monitoring of degradation in tissue engineering.

Cunha-Reis C., El Haj A.J., Yang X. and Yang Y. Journal of Tissue Engineering and Regenerative Medicine.  Vol. 7(1):39-50. January 2013

The aim of the study was to develop a fluorescence-based tracking method, which can visualise the degradation of chitosan-based tissue scaffolds. Tetramethylrhodamine isothiocyanate (TRITC) served as fluorophore and was linked to the chitosan backbone via covalent binding. The degradation process of the biopolymer was determined by the reduction in fluorescence intensity.

Results for TRITC-chitosan scaffolds:

• Biocompatible
• TRITC-chitosan membranes support growth of MG63 bone cell
• Cell viability  was 2x greater compared to non- labelled membranes
• Intensity of fluorescence correlated with weight loss of the scaffold
• Monitored in vitro up to 16 weeks and in vivo over 2 weeks

Conclusion: The degradation process of TRITC-labelled chitosan scaffolds was successfully monitored by using laser scanning confocal microscopy. The loss of fluorescence intensity was proportionally linked to degradation and weight loss of the membranes. Implants composed of fluorophore-labelled biomaterials might be useful for medical surgery, as they allow a non-destructive monitoring of implants of patients after surgery.

Source: http://www.ncbi.nlm.nih.gov/pubmed/22125289

Adipose tissue engineering with human adipose tissue-derived adult stem cells and a novel porous scaffold.

Wang W., Cao B., Cui L. et al., Journal of Biomedical Materials Research Part B: Applied Biomaterials Vol. 101(1):68-75. January 2013

Soft tissue defects are currently treated by transplanting tissue flaps or synthetic substitutes. However, the success of such treatments is often limited due to graft resorption or fibrous capsule formation.
The present study investigated a novel scaffold for human adipose tissue-derived adult stem cells (ADSCs). The scaffold was composed of chitosan and poly(L-glutamic acid) (PLGA), which displays good biocompatibility and high hydrophilicity. The attachment, growth, and differentiation of ADSCs were analysed in vitro. In vivo experiments were performed with immunodeficient SCID mice, which were treated with ADSCs-loaded PLGA-chitosan implants.

Results for PLGA-chitosan scaffolds:

ADSCs attached well on scaffold Deposition of extracellular matrix Good cell proliferation behaviour Adipogenic differentiation potential of ADSCs Formation of adipose-like tissue in SCID mice

Conclusion: The porous scaffold of PLGA-chitosan promoted the attachment, proliferation and differentiation of ADSCs. Six weeks after implanting ADSC-loaded scaffolds in SCID mice, the implants were still intact and well vascularized. Thus, PLGA-chitosan scaffolds might be suitable for adipose tissue engineering.

Source: http://www.ncbi.nlm.nih.gov/pubmed/23090921