Studies on the condensation of depolymerized chitosans with DNA for preparing chitosan-DNA nanoparticles for gene delivery applications.
High molecular weight chitosan (CS) was depolymerized by oxidative degradation with NaNO(2) at room temperature to get 11 samples of CS derivatives of varying molecular weights with a view to assessing their effective molecular weight range for gene delivery applications. Viscosity studies indicated that the molecular weight of the depolymerized CS was proportional to the CS/NaNO(2) ratio. The condensation behavior of DNA/CS complexes at various charge ratios was studied using UV spectroscopy, FTIR, CD, SEM, and AFM. The results indicated that CSs having very low molecular weights and high charge density exhibited strong binding affinity to DNA compared to high molecular weight CSs. However, the very low molecular weight (1.9-7.7 kDa) CSs were found to form aggregates easily even at very low charge ratios. On the other hand, CSs having medium molecular weight (49-51 kDa) and high degree of deacetylation (DD) gave stable uniform-sized nanoparticles. Biological studies carried out with the spherical nano-sized polyplexes formed between CS of 50 kDa (DD of 94%) and pEGFP plasmid DNA at N/P ratio of 5.0 showed excellent gene transfection efficiency at pH 6.5 in HeLa cells without cytotoxicity indicating their potential as gene delivery carriers.
Morris
Viola B
VB
Chemical Sciences and Technology Division, Regional Research Laboratory (now NIIST, Thiruvananthapuram, India), Council of Scientific and Industrial Research, Thiruvananthapuram-695 019, India.|Sree Chitra Thirunal Institute for Medical Sciences and Technology, BMT Wing, Poojappura, Thiruvananthapuram-695 01, India.
Neethu
S
S
Chemical Sciences and Technology Division, Regional Research Laboratory (now NIIST, Thiruvananthapuram, India), Council of Scientific and Industrial Research, Thiruvananthapuram-695 019, India.
Abraham
T E
TE
Chemical Sciences and Technology Division, Regional Research Laboratory (now NIIST, Thiruvananthapuram, India), Council of Scientific and Industrial Research, Thiruvananthapuram-695 019, India.
Pillai
C K S
CKS
Chemical Sciences and Technology Division, Regional Research Laboratory (now NIIST, Thiruvananthapuram, India), Council of Scientific and Industrial Research, Thiruvananthapuram-695 019, India.|Sree Chitra Thirunal Institute for Medical Sciences and Technology, BMT Wing, Poojappura, Thiruvananthapuram-695 01, India.
Sharma
Chandra P
CP
Sree Chitra Thirunal Institute for Medical Sciences and Technology, BMT Wing, Poojappura, Thiruvananthapuram-695 01, India.
D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002417:Cattle; D048271:Chitosan / Q000737:chemistry* / Q000378:metabolism; D004247:DNA / Q000737:chemistry*; D004337:Drug Carriers / Q000737:chemistry; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D006367:HeLa Cells; D006801:Humans; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008969:Molecular Sequence Data; D008970:Molecular Weight; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D014783:Viscosity
D004337:Drug Carriers; D046911:Macromolecular Substances; D004247:DNA; D048271:Chitosan