Allergy Therapeutics click here market aluminium-free SCIT products. “
“Conventional aluminium-containing adjuvants have been used in vaccine formulations for decades but promote poor induction of Th1 or cell-mediated immunity [1] and [2]

and require refrigeration during transportation and storage. Approximately 50% of vaccines are discarded globally, largely due to cold chain disruption [3] and [4]. Therefore, a major objective of vaccine formulation t is to develop a safe, immunogenic composition which addresses the issues of immune bias and stability. Protein-coated microcrystals (PCMCs) are a recent advance in vaccine formulation [5] and have the potential to by-pass the cold chain. Originally developed to stabilise enzymes for

industrial applications [5], [6], [7], [8] and [9], PCMCs are formed by rapid co-precipitation of protein(s) with an amino acid or sugar, producing particles with an inert core microcrystal coated with protein(s) [6], [8] and [9]. Vaccine antigens, loaded onto PCMCs, exhibited much higher resistance to heat stress compared to native antigens [5] and [7]. These reports used PCMC formulations which were instantly soluble in aqueous buffer [5], [6], [7], [8] and [9]. In this study, novel sustained-release PCMCs have been used which are poorly soluble due to modification of their outer surface with sparingly soluble CaP. CaP served as an adjuvant in some early acellular vaccines [10] and [11], and is well-tolerated in man [11], [12], [13], [14], [15] and [16]. CaP also XL184 enhances Th1-biased immunity although this may be antigen-dependent [11], [17] and [18]. Here, the immunogenicity of CaP-modified PCMCs loaded with different model antigens was investigated. DT, a formaldehyde-toxoided antigen [19], [20] and [21], and BSA have been used extensively as model antigens when validating new vaccine formulations [22], [23], of [24] and [25]. The DT preparation was the 2nd international standard

for use in flocculation tests (02/176, NIBSC, UK). CyaA* was purified and characterised as described previously [26], [27] and [28]. BSA was from Sigma and BSA-FITC was from Life Technologies, UK. All reagents were of the highest grade available and were used at rt. The aqueous solution was prepared in endotoxin-free, sterile water (Sigma) and contained 30 mg/ml l-glutamine as the core component of the PCMCs, trehalose and the test antigens, sufficient to give final loadings of 10% and 0.2–0.4%, respectively, in the PCMC preparation. To precipitate PCMCs, 3 ml of the aqueous solution was added drop-wise to 60 ml of rapidly stirred isopropanol and stirring continued for 1 min at 1500 rpm. For CaP-modified PCMCs, the required concentration of NaH2PO4 was included in the aqueous solution and CaCl2 was included in the isopropanol at a 2-fold molar excess compared to NaH2PO4. PCMCs were collected by vacuum filtration onto PVDF hydrophilic 0.