In this era of advanced technology, most of
the drugs available in the market are being synthesised from synthetic
materials either the active ingredients nor excipients or drug carriers. The
supply of the synthetic materials is known to be from the limited sources such
as fossil fuels which will be exhausted in the near future. Thus, generally
this study is going to investigate the alternative biomaterials which is the
natural polysaccharides that can be obtained from the renewable sources.
Nevertheless, the complexity and the inherently
physicochemical characteristics of natural occurring polysaccharides causes
their bioactivities are very difficult to be compared with the synthetic
biomaterials. Plus, the native polysaccharides also showed very limited desirable properties to benefit the
biomedical applications. For example, the hydrophilicity property can retard their
bioactivities. Therefore, the chemical modification in this study with the goal
to enhance the physicochemical properties of natural polysaccharides allows the alteration of the polysaccharides molecular
structure by using alkylation method.
On top of that, there are only very small
percentage of drugs formulated all over the world that able to cross the blood
brain barrier (BBB) and have access to the brain. Through chemical modification
of biomaterials used in drugs formulation, the permeability
of the synthesised drugs to travel into the brain can be upgraded. This is done
by the polysaccharides character changes which rendering them hydrophobic.
In this study, dextran is selected as the
alternative polysaccharide to be employed for biomedical applications. The
three important aspects that has always been the main concern in drugs
formulation include safety, quality, and efficacy. Thus, among the reasons for
dextran being selected to be chemically modified in this project include the
safety and quality profile of dextran was significantly proved in various
clinical uses over the past 50 years. Moreover, in term of for biomedical uses,
dextran has many favourable properties that include great stability,
biocompatibility, and it is biodegradable. Dextran also can be easily accessed
as it is already commercially available in the current market.
Dextran is chemically modified with
alkylglycerols by using the common and frequently used method which is alkylation. Alkylation modification has the
capability to reduce the viscosity and to upgrade the solubility which are
beneficial for the polysaccharides to have better bioactivities. These two
valuable actions are in line with the final goal of the chemical modification
which to produce a modified polysaccharide with the profitable physicochemical
properties in order to be applied in biomedical field.