Biomedical Engineering Reference
In-Depth Information
products. Results showed that the dressing absorbed blood quickly, accel-
erated clotting and enhanced red blood cell adhesion. h is bandage showed
great potential as a haemostatic dressing [110]. Lin
et al.
combined chito-
san with bacterial cellulose to produce membranes on a large scale [111].
Testing of these membranes showed that they inhibited the growth of com-
mon pathogens
E. coli
and
S. aureus
and promoted wound healing [111].
h ese wound dressings may also contain other bioactive molecules such as
the semi-interpenetration hydrogel based on polyacrylamide and chitosan.
h is hydrogel was loaded with growth factors and the antibiotic piperacil-
lin-tazobactam allowing for ef ective wound healing management [112].
In bone tissue engineering, Tanase and colleagues report the syn-
thesis of a chitosan-calcium phosphate matrix
via
a novel biomimetic
co- precipitation method [113]. It was found that these scaf olds were com-
parable to the controls tested making these biomaterials strong candidates
for use in tissue regeneration [113]. Le
et al.
investigated chitosan com-
posites containing precipitated hydroxyapatite particles where the mineral
increased the durability of the compound [114]. h ese composites can
potentially be applied as bone tissue scaf olds [114]. In another study, Lee
and co-workers investigated the ef ects of varying concentrations of chi-
tosan and β-tricalcium phosphate on a collagen matrix [115]. h e study
found that the composite membranes were good candidates for guided
bone regeneration membranes [115]. Moving into the nano-scale, Dorj
and co-workers produced a nanocomposite scaf old of chitosan and nano-
bioactive glass through the method of robocasting [116]. h e study sug-
gested that these composites may i nd utility in bone tissue engineering as
matrices [116]. Liu
et al.
incorporated halloysite nanotubes into chitosan
forming bionanocomposite i lms [88]. h ese i lms have the potential to act
as scaf old materials in tissue engineering. Overall, chitosan is an excellent
compound for use in wound healing/ tissue regeneration [88]. h is is due
to the favourable characteristics of this polymer as evidenced by the many
commercially available dressings which are superior to most wound care
products.
5.7.3
Targeted Delivery Agents
h e application of biopharmaceuticals is hampered by the delivery of bio-
active agents to the intended target. h is could be a result of solubility,
stability, charge and size issues which restricts the choice of an appropriate
delivery method. To date, chitosan and its derivatives have been studied as
peptide, protein, gene, drug (oral, ocular, nasal and buccal), biopharmaceu-
tical, nucleic acid and anticancer biopharmaceutical delivery systems. h is
