Nondestructive testing of defects in adhesive joints

adhesives, cosmetics, detergents, toothpaste, special food products and medical diagnostics.
Polysaccharides possesses distinct chemical and biological properties that include
biocompatibility, biodegradability to harmless products, nontoxicity, physiological inertness,
remarkable affinity to proteins, hemostatic, fungistatic, antitumoral and anticholesteremic
properties [19,20] Chitosan, a copolymer of β (1,4)-D-glucosamine and β(1-4)-N-acetyl-Dglucosamine,
is a non toxic, biodegradable and positively charged polysaccharide widely used as
a support for enzyme immobilization [8,9,10]. Galactomannas have a linear back bone of (1→4)diequatorially
linked β-D-mannose residues, some of which carry single- sugar side chains of α-
L-galactose attached by (1→6) linkages. Guar gums normally have an M/G ratio of ~1.6. Low
molecular weight, acid–free water-soluble polysaccharides (LMWPS), are made by
depolymerization and from this nanoparticles can be made by ionic gelation technique[11, 12].
Important application of polysaccharide nanoparticles is in the controlled release of protein and
peptide drugs, because they show excellent mucoadhesiveness and permeation enhancing effect
across the biological surfaces. Protein/peptide oral drug delivery is complicated process mainly
due to poor intrinsic protein permeability as a result of large molecular weight, degradation by
proteolytic enzymes in the stomach and in the small intestine, and chemical instability [13,14].
Compared with conventional solid-phase supports, nano particulate matrices could have a higher
catalyst loading capacity due to their very large surface areas [15]. Subtilisin is one of the major
proteolytic enzymes having a neutral pH, which is used as a digestive aid in pancreatitis, and used
for wound healing etc. The preparation and properties of subtilisin functionalized biocatalytic
polysaccharide nano particles are reported here.
2. Experimental
2.1 Materials: Chitosan and Guar gum were produced from Sigma (St.Luis, USA). Subtilisin
[Amano, Japan,], Gluteraldehyde and Aerosol-OT [Sigma, St.louis, USA], tripoly phosphate,
solvents such as Isopropanol and all the other reagents are of analytical quality.
2.2 Preparation of polysaccharide nano particles; The polysaccharide nanoparticles were made
by 3 methods such as nano precipitation and cross linking, dialysis and cross linking or by two
phase separation.
2.3 Preparation of subtilisin functionalized polysaccharide nano particles(EFNP) : The sutilisin
solution in phosphate buffer (pH 7.0, 0.1M) was added to a suspension having polysaccharide
nano particles. The enzyme was immobilized by glutaraldehyde coupling and then glycine was
added to remove any unreacted aldehyde groups. The particles were then dialyzed against fresh
phosphate buffer (pH 7.0, 0.1M) for 4 hours to remove the excess cross linking agents.