R. Cortesi et al., GELATIN MICROSPHERES AS A NEW APPROACH FOR THE CONTROLLED DELIVERY OFSYNTHETIC OLIGONUCLEOTIDES AND PCR-GENERATED DNA FRAGMENTS, International journal of pharmaceutics, 105(2), 1994, pp. 181-186
The present paper reports the preparation and characterization of gela
tin microspheres containing (a) a 44-mer single-stranded synthetic oli
gonucleotide, complementary to the HLA-DRA gene (ssDNA-44) and (b) a d
ouble-stranded fragment, 144 bp in length, prepared by the polymerase
chain reaction (PCR) mimicking a region of the HIV-1 LTR (dsDNA-144).
Spherical gelatin microspheres were obtained by a coacervation method,
showing a high percentage of encapsulation yields (over 85%). Size di
stribution analysis of the microspheres produced resulted in an averag
e diameter of 22 mum. In order to analyse the release profiles of both
ssDNA-44 and dsDNA-144 from microspheres, in vitro studies were carri
ed out by using a flow-through cell method. The chemical stability of
dsDNA-144 to the encapsulation procedure steps was in addition demonst
rated by. PCR amplification of the DNA eluted from the gelatin microsp
heres. The reported results indicate that gelatin-based microspheres o
ffer excellent potential as carrier systems for the in vivo administra
tion of both single- and double-stranded DNA molecules.