Fabrication And Evaluation Of Inactivated Influenza Vaccine Encapsulated In Novel Dissolving Microneedles

In the past 100 years,four influenza outbreaks have been killed millions of people.In recent years,avian influenza virus such as H7N9,infected people in small-scale people,and have been high death rate.In addition,the annual seasonal flu led 3 million to 5 million people to serious illness,of which about 250,000 to 500,000 died.Prevention and control situation of influenza is serious.Influenza vaccine is the most effective way to prevent serious consequences of the disease.At present,the vaccination of influenza vaccine in China is mainly intramuscular injection,but intramuscular injection has many shortcomings such as the need for professional medical personnel vaccination,vaccine dosage,pain and cross infection.The need for professional medical personnel inoculation lead to slow large-scale vaccination rate;pain lead to needle fear,especially for children,and low vaccination rate;cross infection lead to increasing blood-borne infectious diseases such as hepatitis B,hepatitis C and AIDS,;high cost of Vaccination also cause low vaccination rate.In addition,influenza vaccine production based on chicken embryo is difficult to quickly meet the influenza pandemic,some subtypes of influenza vaccine immunogenicity is low,vaccination requires a higher dose and multiple immunizations.Newly developed influenza vaccines such as genetically engineered vaccines,subunit vaccines,etc.,have low immunogenicity and have not been approved for use.Therefore,there is an urgent need to find new ways to solve the problems.In this paper,in the severe situation,we have study loaded-influenza vaccine soluble microneedle in vitro and in vivo.we found dissolving microneedle immune system,relieve the pressure on the grim situation facing influenza.Objective We screen dissolving materials for fabrication of loaded influenza dissolving microneedles,and the dissolving microneedles can effectively penetrate the stratum corneum to deliver the influenza vaccine to the skin,causing the immune response to protect animal against influenza virus infection such as influenza H7N9 and seasonal influenza.Methods The dissolving microneedle influenza H7N9 vaccine was fabricated by negative pressure.The integrity and particle size of inactivated influenza H7N9 virus were detected by transmission electron microscopy and dynamic light scattering.Small animal live imaging device detect retention time of soluble microneedles influenza H7N9 vaccine after intradermal injection and intramuscular injection;Animal experiment check out immune reponse.The FITC-labeled influenza vaccine observed distribution of influenza vaccine.The depth of penetration of dissolving microneedles influenza vaccine was detected by laser confocal laser fluorescence microscopy.The dissolving microneedles influenza vaccine were tested for the level of specific antibody and the levels of IL-4 secreted after immunization.In addition,the protective effect of dissolving microneedles influenza H1N1 vaccine was tested.Results Five kinds of soluble influenza H7N9 soluble microneedles were prepared by negative pressure method.Dissolving microneedles from prescription 1 and 5 could effectively pierce pig skin.The results of transmission electron microscopy showed that there was no obvious damage to the virus after reconstitution.The results of dynamic light scattering showed that the size of influenza virus increased after reconstitution,and smaller in the prescription 5.The results showed that in the same dose of influenza vaccine delivered to the skin and muscle,the intradermal antigen have retention time longer than the intramuscle;animal experiments show that dissolving microneedles from prescription 1 and 5 induced immune reponse.We further optimize the prescription of dissolving microneedles.The results show that the microneedles can induce immune response protective effect comparable to intramuscle injection,and has a stronger ability to clear virus in the lung.Conclusion The dissolving microneedle influenza H7N9 vaccine was fabricated and induce immune response.Individual influenza vaccine was delivered by novel dissolving microneedles,the new preparation method can be prepared only in the needle body containing the vaccine of the layered microneedles,the dissolving microneedle Vaccines can effectively pierce pig skin,and induced immune response.This study build foundation for further study of dissopving microneedles influenza vaccine.