Nasal-nanotechnology: revolution for efficient therapeutics delivery

Context: In recent years, nanotechnology-based delivery systems have gained interest to overcome the problems of restricted absorption of therapeutic agents from the nasal cavity, depending upon the physicochemical properties of the drug and physiological properties of the human nose.

Objective: The well-tolerated and non-invasive nasal drug delivery when combined with the nanotechnology-based novel formulations and carriers, opens the way for the effective systemic and brain targeting delivery of various therapeutic agents. To accomplish competent drug delivery, it is imperative to recognize the interactions among the nanomaterials and the nasal biological environment, targeting cell-surface receptors, drug release, multiple drug administration, stability of therapeutic agents and molecular mechanisms of cell signaling involved in patho-biology of the disease under consideration.

Methods: Quite a few systems have been successfully formulated using nanomaterials for intranasal (IN) delivery. Carbon nanotubes (CNTs), chitosan, polylactic-co-glycolic acid (PLGA) and PLGA-based nanosystems have also been studied in vitro and in vivo for the delivery of several therapeutic agents which shown promising concentrations in the brain after nasal administration.

Results and conclusion: The use of nanomaterials including peptide-based nanotubes and nanogels (NGs) for vaccine delivery via nasal route is a new approach to control the disease progression. In this review, the recent developments in nanotechnology utilized for nasal drug delivery have been discussed.     

地西泮在体鼻腔吸收动力学及薄荷醇对其吸收促进作用的研究

目的：研究地西泮鼻腔吸收的主要影响因素、吸收动力学及促透剂薄荷醇对其吸收的影响。方法：建立家兔在体鼻腔循环吸收的动物模型,取样时间为0、5、10、15、30、45、60、75、90 min,计算药物吸收速率常数K、吸收半衰期（t1/2）及药物吸收率。研究在鼻腔灌流液体积、循环液流速和pH值一定的条件下,地西泮的质量浓度、吸收促进剂薄荷醇对地西泮鼻腔吸收的影响。结果：在鼻腔灌流液体积为5 ml,循环液流速2.0 ml/min,循环液的pH值在5.9～6.1的中性吸收环境下,地西泮质量浓度在0.25～1.00 g/L时,随着地西泮质量浓度的增加,药物吸收速率常数K增加不明显,t1/2及药物吸收率变化不大;薄荷醇含量为0.2%时对地西泮鼻腔吸收有最佳的促进效果[药物吸收速率常数K为（0.442 4±0.002 3）/h],且能加快地西泮的吸收[t1/2为（0.32±0.07）h）],缩短地西泮的t1/2;0.2%～0.4%范围内,随薄荷醇质量浓度的增加,药物吸收速率常数K反而减小。结论：地西泮可以经鼻腔吸收,鼻腔吸收的机制为被动扩散;0.2%薄荷醇能促进地西泮的鼻腔吸收。     

Vaccination evokes gender-dependent protection against tularemia infection in C57BL/6Tac mice

Francisella tularensis (Ft) is a Category A biothreat agent for which there currently is no FDA-approved vaccine. Thus, there is a substantial effort underway to develop an effective tularemia vaccine. While it is well established that gender can significantly impact susceptibility to primary infection, the impact of gender on vaccine efficacy is not well established. Thus, development of a successful vaccine against tularemia will require an understanding of the impact gender has on vaccine-induced protection against this organism. In this study, a role for gender in vaccine-induced protection following Ft challenge is identified for the first time. In the present study, mucosal vaccination with inactivated Ft (iFt) LVS elicited gender-based protection in C57BL/6Tac mice against respiratory challenge with Ft LVS. Specifically, vaccinated male mice were more susceptible to subsequent Ft LVS challenge. This increased susceptibility in male mice correlated with increased bacterial burden, increased tissue inflammation, and increased proinflammatory cytokine production late in post-challenge infection. In contrast, improved survival of iFt-vaccinated female mice correlated with reduced bacterial burden and enhanced levels of Ft-specific Abs in serum and broncho-alveolar lavage (BAL) fluid post-challenge. Furthermore, vaccination with a live attenuated vaccine consisting of an Ft LVS superoxide dismutase (SodB) mutant, which has proven efficacious against the highly virulent Ft SchuS4 strain, demonstrated similar gender bias in protection post-Ft SchuS4 challenge. Of particular significance is the fact that these are the first studies to demonstrate that gender differences impact disease outcome in the case of lethal respiratory tularemia following mucosal vaccination. In addition, these studies further emphasize the fact that gender differences must be a serious consideration in any future tularemia vaccine development studies.     

Intranasal immunization with protective antigen of Bacillus anthracis induces a long-term immunological memory response

Although intranasal vaccination has been shown to be effective for the protection against inhalational anthrax, establishment of long-term immunity has yet to be achieved. Here, we investigated whether intranasal immunization with recombinant protective antigen (rPA) of Bacillus anthracis induces immunological memory responses in the mucosal and systemic compartments. Intranasal immunization with rPA plus cholera toxin (CT) sustained PA-specific antibody responses for 6 months in lung, nasal washes, and vaginal washes as well as serum. A significant induction of PA-specific memory B cells was observed in spleen, cervical lymph nodes (CLNs) and lung after booster immunization. Furthermore, intranasal immunization with rPA plus CT remarkably generated effector memory CD4⁺ T cells in the lung. PA-specific CD4⁺ T cells preferentially increased the expression of Th1- and Th17-type cytokines in lung, but not in spleen or CLNs. Collectively, the intranasal immunization with rPA plus CT promoted immunologic memory responses in the mucosal and systemic compartments, providing long-term immunity.     

双价痢疾工程疫苗经粘膜免疫动物的实验研究

目的探讨不同粘膜免疫途径对2株痢疾工程疫苗免疫效果的影响.方法用FSM-2117或FS-5416以4×107CFU/只分别经滴鼻、灌胃和小肠内免疫小鼠,3次免疫后7?d分离小鼠脾、派伊尔结(PP)、肠系膜中心淋巴结(MLN)、小肠淋巴细胞固有层(LPL)、鼻通道(NP)及NALT淋巴细胞,用BA-ELISASPOT法检测其特异性抗FSM-2117或FS-5416全菌抗原的IgA、IgG-ASC(抗体分泌细胞)数量.结果2株疫苗经鼻内免疫都诱发了鼻粘膜相关淋巴组织、胃肠粘膜相关淋巴组织以及代表系统免疫反应的脾淋巴细胞全菌抗原特异性IgA、IgG-ASC的显著增加(P＜0.05和0.01).小肠内免疫后,可有效诱发肠粘膜局部以及脾淋巴细胞全菌抗原特异性IgA、IgG-ASC的显著增加(P＜0.01),但不能刺激鼻粘膜局部淋巴细胞的特异性ASC反应.结论2株疫苗经鼻粘膜免疫均可诱导NALT和GALT及系统免疫反应的发生,是一个可行的免疫途径.     

双价痢疾菌苗滴鼻免疫小鼠诱导粘膜与系统免疫反应

目的探讨双价痢疾菌苗滴鼻免疫后对小鼠不同粘膜部位和系统免疫部位的影响.方法BALB/c小鼠随机分为3组,每组20只,FSM-2117或FS-54164×107CFU/只经滴鼻途径免疫小鼠,间隔2w,3次免疫后7d活杀,分离NALT、鼻通道、脾、小肠PP及MLN淋巴细胞,采用流式细胞术检测其淋巴细胞表型的变化;收集鼻咽、肺、肠、生殖道冲洗液和血清,采用ELISA法检测其中特异性抗福氏、宋内氏LPSIgA和IgG.结果两株菌苗经鼻内免疫都诱发了鼻咽、肺、胃肠道和生殖道等不同粘膜部位及血清中特异性抗福氏、宋内氏LPSIgA、IgG的显著增加(P＜0.01);NALT、NP和PP淋巴细胞中CD3+T细胞显著增加,其中以CD4+T细胞增加为主;FSM-2117免疫组的脾细胞中B220+细胞显著增加,而FS-5416免疫组的脾细胞中CD3+T细胞显著增加.结论两株菌苗经鼻粘膜免疫均可诱导不同粘膜部位及系统免疫反应的发生,鼻粘膜是一个安全有效的免疫途径.     

重组沙门菌表达结核分枝杆菌ESAT-6及其特异性免疫应答分析

Objective To determine the immune responses induced by recombinant Salmonella ty-phimurium expressing the secreting antigen ESAT-6 of Mycobacterium tuberculosis. Methods ESAT-6 cod-ing gene was cloned and identified by PCR and sequencing. Prokaryotic expression plasmid pYA33-esat car-rying the ESAT-6 coding sequence was constructed firstly and electro-transformed into an attenuated strain X4550 of Salmonella typhimurium, the recombinant bacteria was named as X4550(33-esat). C57BL/6 mice were immunized intranasally (I. N) with 108 CFU recombinant bacteria at day 0 and 18. Cells from spleen, lung, mesenteric lymph node (MLN) and Peyer's patch (PP) were collected from mice after second immu-nization, and the specific IFN-γ-secreting cells and IL-4-secreting cells were detected by ELISPOT assay u-sing ESAT-6 peptide as stimulus. Furthermore, CTL effects were in vivo evaluated by CFSE assay. Results The results showed that cellular immune responses specific for ESAT-6 could be detected by ELISPOT assay. In lung and PP cells, immune responses against ESAT-6 were biased toward Th1 type, the frequency of IFN-γ-secreting cells was much higher than that of IL-4-secreting cells. In splenocytes and MLN cells, the anti-gen specific immune responses acted as Thl and Th2 balance, the frequency of IFN-γ-secreting cells was close to that of IL-4-secreting cells. CFSE assay indicated that recombinant bacteria could induce the high level of CTL effects specific for ESAT-6 peptide. Conclusion These results suggested that recombinant Sal-monella typhimurium X4550(33-esat) not only can induce cellular immune responses, but also can elicit specific CTL responses after I. N immunization. It also provided the useful information for the control of infec-tious disease of tuberculosis.