Preparation and optimization of carboxymethyl sago starch hydrogel as a potential carrier for Newcastle disease virus vaccine
Carboxymethyl sago starch (CMSS) is an important water-soluble polysaccharide in many applications in food and non-food industries. When crosslinked, CMSS produce three-dimensional polymeric network hydrogel which has the ability to retain a large amount of solution inside its network. Newcastle...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2018
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/98057/1/FS%202020%2033%20UPMIR.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | Carboxymethyl sago starch (CMSS) is an important water-soluble
polysaccharide in many applications in food and non-food industries. When
crosslinked, CMSS produce three-dimensional polymeric network hydrogel
which has the ability to retain a large amount of solution inside its network.
Newcastle disease (ND) is a highly contagious disease which causes devastating
losses in poultry industries worldwide. This disease is caused by virulent strains
of avian paramyxovirus and can be controlled by the used of Newcastle disease
virus (NDV) vaccine. However, NDV vaccine is highly sensitive towards high
temperature and need a proper storage chain in order to secure its efficacy. In
this study, CMSS hydrogel was prepared by dissolving CMSS in HCl solution
under vigorous stirring to form hydrogel. This CMSS hydrogel was then used
to encapsulate NDV. Four parameters were studied to optimize the preparation
of CMSS hydrogel, which were the effect of the percentage of CMSS,
concentration of the HCl solution, reaction time and reaction temperature. The
percentage of gel content and degree of swelling become the indicators studied
in each parameter. 60% of CMSS in 2.0M HCl solution for 12 hours reaction
time at room temperature were the optimum conditions for the preparation of
CMSS hydrogel which resulted in 70.40 % of gel content with 50.79 (g/g)
degree of swelling. The CMSS hydrogel was characterized by using Fourier
transform infrared (FT-IR), thermogravimetric analysis (TGA), X-Ray
diffraction (XRD) and scanning electron microscopy (SEM). FTIR spectrum of
CMSS showed an additional absorption band at 1597 cm-1 indicating the
substitution of CH2COO-Na+ group on the starch molecular chain during
carboxymethylation. While the spectrum of CMSS hydrogel showed an additional sharp absorption band at 1723 cm-1 indicating that the Na in CMSS
being exchanged to H from hydrochloric acid solution. TGA thermograms
showed that carboxymethylation reaction shifted the maximum decomposition
of sago starch to a lower temperature from 309.57 ºC to 295.33 ºC. However,
the presence of crosslinkages in CMSS hydrogel gave better thermal stability
when compared to CMSS which gave maximum temperature of decomposition
at 330.22 ºC with 60.22 % major weight loss. X-ray diffraction pattern of CMSS
showed that the semi-crystalline structure of sago starch completely destroyed
after underwent carboxymethylation reaction. SEM image showed distorted and
irregular shape of modified sago starch after carboxymethylation. Whereas,
CMSS hydrogel showed a spongy surface with empty space called pores in
structure and interconnected to each other to form networks. CMSS hydrogel
exhibited pH-sensitive behavior as it showed highest swelling at PBS pH 7 but
shrank at low pH and acidic solution. Two parameters were carried out in order
to investigate the loading and release of encapsulated NDV vaccine in CMSS
hydrogel which were the amount of CMSS hydrogel and loading time. 0.02 g
of CMSS hydrogel at 30 minutes loading time were the optimum conditions in
this study which gave 69.23% of loading and 86.26% of release of NDV
vaccine. The stability study of NDV-CMSS hydrogel showed that CMSS
hydrogel successfully able to protect the NDV vaccine and retained its stability
when stored up to 30 days at room temperature. High thermal properties of
CMSS hydrogel with porous structure has allowed NDV vaccine to be trapped
inside its three-dimensional matrix. CMSS hydrogel successfully protected the
NDV vaccine from deterioration due to high temperature of its surrounding. In
conclusion, CMSS hydrogel showed an outstanding result as NDV vaccine
carrier which gave ample protection to NDV vaccines. CMSS hydrogel can
improve current NDV vaccine storage and delivery without depending on cold
chain system. |
|---|