Publications in September & October 2014

In September and October, 276 chitosan-related articles have been released. The main topics addressed chitosan in evaluation studies, pharmaceutical preparations, nanoparticles and tissue engineering. The highest number of publications was performed by the leading nations China (73 articles), USA (28) and India (22). German scientists published 8 articles, placing them in the top-ten list.

Table: Scientific journals publishing the highest number of chitosan-related articles in September and October 2014.
Source: GoPubMed

Several promising articles were published on chitosan scaffolds in the field of tissue-engineering. Since chitosan has advantageous properties like good biological compatibility and resorbability and is bacteriostatic and fungistatic, various application options are possible. The key findings of three selected publications are summarized below.

Incorporation of copper into chitosan scaffolds promotes bone regeneration in rat calvarial defects.

D'Mello S., Elangovan S., Hong L., et al.; Journal of Biomedical Materials Research Part B: Applied Biomaterials. doi: 10.1002/jbm.b.33290; September 2014

This in vivo study analyzed chitosan and copper- crosslinked chitosan scaffolds to determine their efficiency in bone tissue regeneration. Fisher 344 rats with severe calvarial defects (5 mm diameter) were treated with scaffold implants made of chitosan or copper-chitosan. A control group of animals remained untreated. The formation of new bone tissue was investigated after 4 weeks by using microcomputed tomography (micro-CT) and histological sections.

Result:

Animals treated with copper-chitosan implants display a significantly elevated bone regeneration rate compared to untreated or chitosan-treated animals.

• Mirco-CT analyses:  eleven-fold increase in new bone volume /  total volume (BV / TV) ratio
• Histological analyses: two-fold increase in BV/TV

Thus, copper ions might be a useful modification of chitosan scaffolds, as they clearly improve bone tissue regeneration.

Source: http://www.ncbi.nlm.nih.gov/pubmed/25230382

In vitro evaluation of cell-seeded chitosan films for peripheral nerve tissue engineering.

Wrobel S., Serra S.C., Ribeiro-Samy S. et al.; Tissue engineering. Part A. Vol. 20 (17-18): 2339-49; September 2014

Tissue-engineered nerve grafts display a promising tool in the treatment of transected peripheral nerves. The aim of this study was to develop a novel entubulation strategy for damaged nerve fibers by using chitosan films. These films were designed as hollow channels in order to seed Schwann cells (SCs) or bone-marrow-derived mesenchymal stromal cells (BMSCs) into their cavity. Both glial cell types are candidates for peripheral nerve tissue regeneration.

Rolling chitosan film:

Matrix for glial cells are involved in nerve tissue regeneration. Fig. A:  degree of acetylation determines degradation rate of  chitosan films Fig. B:  seeded glial cell (SCs, BMSCs)

Chitosan films were designed with a low degree of acetylation (5 %) and display good cell-adhesion and cell proliferation properties. By seeding SCs and BMSCs on the film surface, a massive neurite outgrowth from dissociated sensory neurons was observed..

Conclusion: Chitosan films can serve as nerve guiding channel, as they improve growth and adhesion of preseeded glial cells.

Source: http://www.ncbi.nlm.nih.gov/pubmed/24606318

Physicochemical modulation of chitosan-based hydrogels induces different biological responses: interest for tissue engineering.

Rami L., Malaise S., Delmond S. et al.; Journal of Biomedical Materials Research Part A. Vol. 102; 10: 3666–3676; October 2014

The objective of this study was to investigate physio-chemical, mechanical and biological properties of chitosan-based hydrogels by modifying the polymer concentration, the level of chitosan-acetylation and the process of gelation.

Result:

The structure, biological degradation rate and tissue regeneration efficiency of chitosan-based hydrogels is largely determined by their degree of acetylation.

Source: http://www.ncbi.nlm.nih.gov/pubmed/24293114