Optimization of stability, encapsulation, release, and cross-priming of tumor antigen-containing PLGA nanoparticles.
OBJECTIVE
In order to investigate Poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NP) as potential vehicles for efficient tumor antigen (TA) delivery to dendritic cells (DC), this study aimed to optimize encapsulation/release kinetics before determining immunogenicity of antigen-containing NP.


METHODS
Various techniques were used to liberate TA from cell lines. Single (gp100) and multiple (B16-tumor lysate containing gp100) antigens were encapsulated within differing molecular weight PLGA co-polymers. Differences in morphology, encapsulation/release and biologic potency were studied. Findings were adopted to encapsulate fresh tumor lysate from patients with advanced tumors and compare stimulation of tumor infiltrating lymphocytes (TIL) against that achieved by soluble lysate.


RESULTS
Four cycles of freeze-thaw + 15 s sonication resulted in antigen-rich lysates without the need for toxic detergents or protease inhibitors. The 80 KDa polymer resulted in maximal release of payload and favorable production of immunostimulatory IL-2 and IFN-γ. NP-mediated antigen delivery led to increased IFN-γ and decreased immunoinhibitory IL-10 synthesis when compared to soluble lysate.


CONCLUSIONS
Four cycles of freeze-thaw followed by 15 s sonication is the ideal technique to obtain complex TA for encapsulation. The 80 KDa polymer has the most promising combination of release kinetics and biologic potency. Encapsulated antigens are immunogenic and evoke favorable TIL-mediated anti-tumor responses.
Department of Dermatology, Yale University, New Haven, Connecticut 06520-8260, USA.
Shashi
S
Prasad
Virginia
V
Cody
Jennifer K
JK
Saucier-Sawyer
Tarek R
TR
Fadel
Richard L
RL
Edelson
Martin A
MA
Birchall
Douglas J
DJ
Hanlon
D000818:Animals; D000951:Antigens, Neoplasm / Q000008:administration & dosage / Q000276:immunology*; D045744:Cell Line, Tumor; D018920:Coculture Techniques; D005260:Female; D019344:Lactic Acid / Q000737:chemistry*; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D011100:Polyglycolic Acid / Q000737:chemistry*; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer
D000951:Antigens, Neoplasm; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid