Microneedles with intrinsic immunoadjuvant properties: microfabrication, protein stability, and modulated release.

摘要

PURPOSE: 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 degrees 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.