(620as) Hydrogel Ulva-Chitosan, Alternative Use of Algae As Bio-Injectable Material

Hydrogel Ulva-Chitosan, Alternative Use of Algae Ulva as Bio-Injectable Material

Tania Kristanty ¹⁾ Farida Arisa ²⁾

1. Student, Chemical Engineering Department, Universitas Gadjah Mada, 55281
2. Student, Chemical Engineering Department, Universitas Gadjah Mada, 55281

Introduction.Indonesia is a country that has large biodiversity but unfortunately the utilizations of that biodiversity are still sporadic. Wise use of biodiversity is important for sustainable development. The largest biodiversity is in the sea. For example, marine alga is the most abundant source of organic carbon in the biosphere, because its cell wall mainly consists of interconnecting polysaccharides. Ulva contains the functional acidic polysaccharide that has various functions. Beside that there is Chitin, a polysaccharide found in crab shells and shellfish which is being a marine waste. Chitin and chitosan(obtained by alkaline deacetylation of chitin) revealed that they possessed biological activities such as anti-bacterial effects. This research adds value to crab shell waste. One resource that is considered to have potential as a hydrogel material is Ulva lactuca.

Meanwhile, many researchers have reported various biological activities for ulvan that including anti-coagulant (Mao et al., 2009), anti-inflammatory (Leiro et al., 2010), anti-oxidant (Qi et al., 2006),immunostimulatory (Leiro et al., 2007), and anti-hyperlipidemic (Pengzhan et al., 2003) properties. However, despite the abundance and availability of green seaweeds or ulva and chitosan, relatively few studies have been performed on the molecular structures and the bioactivities of their sulfated polysaccharides. So, there is limited information available about that. Combination of both yields a hydrogel that can be use as a bioinjectable material because Chitosan has amine functional group (-NH2) which is highly reactive and positively charged, so it is able to bind to negative charge of Ulva lactuca.

In the medical world, surgery becomes an option in the medical world as a solution of the wound healing. However, the healing process will take a long time and not all operations are successful as expected and may pose a risk. For that, we need a new method in wound healing in order to minimize operating with the injection technique by the use of hydrogel as bio injectable material because it is capable of providing nutrients and place for the cell to live at the same place so that healing can take place. As injectable hydrogel material becomes very promising in the future as it has biocompatibility and easily applied without having to go through a complicated surgical procedure. (Bae, 2013).

Some previous researches have proof that ulva forms a hydrogel by combining it with another substance like Boron. However, the boron complex forms only at pH values over 9 (Lahaye et al., 1998). The ulvan-chitosan polyion complex-type gel was stable over a wide range of pH values. The reason for this may be that the polyion complex has many cross-linking groups (e.g., carboxyl groups and amino groups) in a single molecule. So, combining ulva and chitosan as a biohydrogel has side advantage.

Experimental.Ulvalactucawill be extracted by the combination of both alkali and hot water extraction. The aqueous solution of ulva extract will be mixed with acidic solution of chitosan to form hydrogel.Amino group on chitosan will react with polysaccharides from Ulva lactuca to form a hydrogel with the help of cross-linker (gluteraldehyde) which is intended to strengthen the bond of hydrogel.

Some tests should be done to know the characteristic and availability of this hydrogel as bioinjectable material. The tests consist of toxicity test, both in vitro and preliminary in vivo, which are held in the optimum condition of hydrogel, these test are on the process. The gel characteristic is obtained from the gelation ratio data or swelling ratio, and the gel morphology is obtained from SEM. To know the characteristic of ulva, there is moisture and ash content test.

Results and Discussion.Moisture content of Ulva: 19.33%; Ash Content of Ulva: 67.33%;

Table 1. Swelling Ratio Data

Thus, with the addition of chitosan, the swelling ratio is higher and the structure is better. With the addition of glutaraldehyde, the swelling ratio is lower but the structure is more rigid. Without the addition of glutaraldehyde, the swelling ratio is high, which means it can absorb a lot of nutrition, but its structure is weak. The specific function of ulva is coating the chitosan.

Conclusion.The idea to do research that utilizes the wealth of ulva and chitosan become hydrogel as bio-injectable material that has benefit to human.

References.

Acknowledgement.The authors thank to Yuni Kusumastuti, S.T.,M.Eng.,D.Eng. as supervisor of our research.