Alternative delivery of a thermostable inactivated polio vaccine.

In the near future oral polio vaccine (OPV) will be replaced by inactivated polio vaccine (IPV) as part of the eradication program of polio. For that reason, there is a need for substantial amount of safe and more affordable IPV for low-income countries. Bioneedles, which are biodegradable mini-implants, have the potential to deliver vaccines outside the cold-chain and administer them without the use of needles and syringes. In the current study, Bioneedles were filled with IPV, subsequently lyophilized, and antigenic recoveries were determined both directly after IPV-Bioneedle preparation as well as after elevated stability testing. Further, we assessed the immunogenicity of IPV-Bioneedles in rats and the residence time at the site of administration. Trivalent IPV was formulated in Bioneedles with recoveries of 101±10%, 113±18%, and 92±15%, respectively for serotypes 1, 2 and 3. IPV in Bioneedles is more resistant to elevated temperatures than liquid IPV: liquid IPV retained less than half of its antigenicity after 1 day at 45°C and IPV in Bioneedles showed remaining recoveries of 80±10%, 85±4% and 63±4% for the three serotypes. In vivo imaging revealed that IPV administered via Bioneedles as well as subcutaneously injected liquid IPV showed a retention time of 3 days at the site of administration. Finally, an immunogenicity study showed that IPV-filled Bioneedles are able to induce virus-neutralizing antibody titers similar to those obtained by liquid intramuscular injection when administered in a booster regime. The addition of LPS-derivate PagL in IPV-filled Bioneedles did not increase immunogenicity compared to IPV-Bioneedles without adjuvant. The current study demonstrates the pre-clinical proof of concept of IPV-filled Bioneedles as a syringe-free alternative delivery system. Further pre-clinical and clinical studies will be required to assess the feasibility whether IPV-Bioneedles show sufficient safety and efficacy, and may contribute to the efforts to eradicate and prevent polio in the future.

Solid bioneedle-delivered influenza vaccines are highly thermostable and induce both humoral and cellular immune responses.

The potential of bioneedles to deliver influenza vaccines was investigated. Four influenza vaccine formulations were screened to determine the optimal formulation for use with bioneedles. The stability of the formulations after freeze-drying was checked to predict the stability of the influenza vaccines in the bioneedles. Subunit, split, virosomal and whole inactivated influenza (WIV) vaccine were formulated and lyophilized in bioneedles, and subsequently administered to C57BL/6 mice. Humoral and cellular immune responses were assessed after vaccination. The thermostability of lyophilized vaccines was determined after one-month storage at elevated temperatures. Bioneedle influenza vaccines induced HI titers that are comparable to those induced by intramuscular WIV vaccination. Delivery by bioneedles did not alter the type of immune response induced by the influenza vaccines. Stability studies showed that lyophilized influenza vaccines have superior thermostability compared to conventional liquid vaccines, and remained stable after one-month storage at 60°C. Influenza vaccines delivered by bioneedles are a viable alternative to conventional liquid influenza vaccines. WIV was determined to be the most potent vaccine formulation for administration by bioneedles. Lyophilized influenza vaccines in bioneedles are independent of a cold-chain, due to their increased thermostability, which makes distribution and stockpiling easier.

Syringe free vaccination with CAF01 Adjuvated Ag85B-ESAT-6 in Bioneedles provides strong and prolonged protection against tuberculosis.

Bioneedles are small hollow sugar based needles administered with a simple compressed air device. In the present study we investigate how incorporation of a subunit vaccine based on TB vaccine hybrid Ag85B-ESAT-6 adjuvated with CAF01 into Bioneedles affects its immunogenicity as well as its ability to protect against TB in a mouse model. The CMI response measured by IFN-γ and antigen specific CD4+ T-cells was, two weeks after the last vaccination, significantly lower in the group immunized with Bioneedle-incorporated vaccine compared to the conventional vaccine, using syringe and needle. However, at four, nine and 52 weeks after vaccination we observed similar high IFN-γ levels in the Bioneedle group and the group vaccinated using syringe and needle and comparable levels of antigen specific T-cells. Furthermore, the protective efficacy for the two vaccination methods was comparable and similar to BCG vaccination both six and 52 weeks after vaccination. These results therefore advocate the further development of the Bioneedle devises and applicators for the delivery of human vaccines.

Bioneedles as alternative delivery system for hepatitis B vaccine.

An alternative vaccine delivery system for needle injections is the Bioneedle. Hepatitis B surface antigen (HBsAg) was formulated with Bioneedles. Three formulations were used: plain antigen, HBsAg adjuvated with aluminum hydroxide and HBsAg with LPS-derived lpxL1. Bioneedles with HBsAg-lpxL1 were the most stable and the most immunogenic formulations. The conventional liquid alum adjuvated vaccine lost 40% of its antigenicity after 1week at 50°C whereas the HBsAg-lpxL1 Bioneedles showed no significant decrease after 3 weeks at 50°C. In vivo studies revealed that the HBsAg-lpxL1 Bioneedle formulations induced comparable IgG titers as conventional liquid formulations after 2 immunizations, but higher IgG2a titers were found already after 1 immunization. The in vivo and in vitro studies showed that the Bioneedle is an attractive alternative for needle injections of HBsAg vaccines.

Bioneedles as vaccine carriers.

Bioneedles are small hollow mini implants fabricated from biodegradable polymers which can be filled with antigen. Bioneedles can be used for vaccination without syringes and needles. Formulations have been prepared containing tetanus toxoid with and without aluminum phosphate. Stability and immunogenicity of Bioneedles were compared with liquid formulations. The antigen, when formulated in Bioneedles, retained fully its antigenicity up to 60 degrees C for 1 week whereas the antigen, in its liquid form, lost all activity at 60 degrees C after 1 week. After 3 weeks at 60 degrees C, a recovery of 60% was still found in the Bioneedles. Mice injected with Bioneedles with adjuvanted tetanus toxoid showed a comparable functional antibody response to the group receiving conventional liquid injections. This response was achieved with a four times lower antigen concentration when using the Bioneedles compared to the regular injections. We conclude that Bioneedles are good alternatives for injections using needles and syringes.

Development and assessment of mini projectiles as drug carriers.

This paper describes a novel technology for the delivery of drugs into the subcutaneous and intramuscular tissue of farmed animals. The technology comprises small, hollow mini projectiles into which drug formulations can be loaded and administered using compressed air from an administration device which is held a few millimeters (3-10 mm) from the surface of the animals' skin. The design of the mini projectiles and administration procedure allows administration without contacting the skin, thereby avoiding cross-contamination between handlings and ensuring safe injection practice in livestock. In vitro experiments are described which investigate the parameters that affect mini projectile penetration into excised porcine and bovine skin. These include shape and weight of the mini projectiles and species type and injection site of the animal. An in vitro skin model for assessing mini projectile administration is described which permits visualization of the penetration of the mini projectiles through excised bovine or porcine skin into an underlying tissue simulant made from gelatin. The quantities of energy necessary to inject mini projectiles through excised porcine and bovine skin into the tissue simulant of the in vitro skin model were determined. The paper also describes the processes that occur during the administration of mini projectiles. The results suggest that tissue damage caused during administration of mini projectiles is comparable to the tissue damage caused by conventional syringe-needle injections. Finally, three different formulations of the model vaccine BSA, without adjuvant, are loaded into mini projectiles and administered to pigs. A seroconversion was shown for all three formulations, thus demonstrating proof of concept for the miniprojectiles.