Microneedles with intrinsic immunoadjuvant properties: microfabrication, protein stability, and modulated release.
OBJECTIVE
Intradermal immunization using microneedles requires compatible immunoadjuvant system. To address this challenge, we investigated microneedles coated with polyphosphazene polyelectrolyte, which served both as microfabrication material and an immunoadjuvant compound.


METHODS
Coated microneedles were fabricated by depositing formulations containing Poly[di(carboxylatophenoxy)phosphazene], PCPP, on metal shafts, and their physico-chemical characterization was conducted.


RESULTS
Microfabrication of PCPP-coated microneedles exhibited strong dependence on protein-PCPP interactions in solutions and allowed for high efficiency of protein encapsulation. 70°C thermal inactivation studies demonstrated a remarkable increase in functional stability of protein in coated microneedles compared to solution formulation. A potential for modulation of protein release from coated microneedles has been demonstrated through ionic complexation of PCPP with small ions.


CONCLUSIONS
Microneedles containing PCPP coatings provide improved protein stability, modulated release, and protein-friendly microfabrication process.
Andrianov
Alexander K
AK
Research & Development, Apogee Technology, Inc., 129 Morgan Drive, Norwood, Massachusetts 02062, USA. aandrianov@apogeebio.com
Marin
Alexander
A
DeCollibus
Daniel P
DP
D000276:Adjuvants, Immunologic / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D007114:Immunization / Q000295:instrumentation / Q000379:methods; D007271:Injections, Intradermal; D008845:Microinjections / Q000295:instrumentation / Q000379:methods; D009339:Needles; D009943:Organophosphorus Compounds / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D055550:Protein Stability; D012710:Serum Albumin, Bovine / Q000008:administration & dosage; D012995:Solubility; D013678:Technology, Pharmaceutical / Q000379:methods*; D013997:Time Factors; D014612:Vaccines / Q000008:administration & dosage / Q000276:immunology
D000276:Adjuvants, Immunologic; D009943:Organophosphorus Compounds; D011108:Polymers; D014612:Vaccines; C546078:poly(di(carboxylatophenoxy)phosphazene); D012710:Serum Albumin, Bovine