Adsorption of a novel recombinant glycoprotein from HIV (Env gp120dV2 SF162) to anionic PLG microparticles retains the structural integrity of the protein, whereas encapsulation in PLG microparticles does not.
OBJECTIVE
To evaluate the delivery of a novel HIV-1 antigen (gp120dV2 SF162) by surface adsorption or encapsulation within polylactide-co-glycolide microparticles and to compare both the formulations for their ability to preserve functional activity as measured by binding to soluble CD4.


METHODS
Poly(lactide-co-glycolide) microparticles were synthesized by a water-in-oil-in-water (w/o/w) emulsification method in the presence of the anionic surfactant dioctylsulfosuccinate (DSS) or polyvinyl alcohol. The HIV envelope glyocoprotein was adsorbed and encapsulated in the PLG particles. Binding efficiency and burst release measured to determine adsorption characteristics. The ability to bind CD4 was assayed to measure the functional integrity of gp120dV2 following different formulation processes.


RESULTS
Protein (antigen) binding to PLG microparticles was influenced by both electrostatic interaction and other mechanisms such as hydrophobic attraction and structural accommodation of the polymer and biomolecule. The functional activity as measured by the ability of gp120dV2 to bind CD4 was maintained by adsorption onto anionic microparticles but drastically reduced by encapsulation.


CONCLUSIONS
The antigen on the adsorbed PLG formulation maintained its binding ability to soluble CD4 in comparison to encapsulation, demonstrating the feasibility of using these novel anionic microparticles as a potential vaccine delivery system.
Singh
Manmohan
M
Chiron Vaccines, Chiron Corporation, Emeryville, California 94608, USA. manmohan_singh@chiron.com
Chesko
James
J
Kazzaz
Jina
J
Ugozzoli
Mildred
M
Kan
Elaine
E
Srivastava
Indresh
I
O'Hagan
Derek T
DT
D000327:Adsorption; D000818:Animals; D015704:CD4 Antigens / Q000378:metabolism; D016466:CHO Cells; D006224:Cricetinae; D004339:Drug Compounding / Q000379:methods; D015699:HIV Envelope Protein gp120 / Q000737:chemistry* / Q000378:metabolism*; D015497:HIV-1 / Q000502:physiology; D008863:Microspheres; D011485:Protein Binding / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry* / Q000493:pharmacokinetics
D015704:CD4 Antigens; D015699:HIV Envelope Protein gp120; D011994:Recombinant Proteins