Selective Targeting of Nanobody-Modified Gold Nanoparticles to Distinct Cell Types.

Nanobody-modified gold nanoparticles were used to explore their ability to achieve selective targeting in vitro and in vivo to distinct cell type(s), based on the specificity of the nanobody that was installed. We developed conjugation methods that exploit click chemistry for octahedral ∼50 nm gold nanoparticles and chiral ∼180 nm gold nanoparticles. We determined that each of these particles could be modified with ∼75 and ∼330 nanobodies, respectively. Particle-bound nanobodies retain their antigen binding capacity. After conjugation of the mouse Class II MHC-specific nanobody VHH7 to chiral gold nanoparticles, selective targeting of Class II MHC-positive cell types was observed in vitro by fluorometric assays and by dark-field microscopy. Upon installation of the positron emission tomography (PET) isotopes 89Zr or 64Cu on nanobody-modified gold nanoparticles and retro-orbital injection of the radiolabeled particles, we observed accumulation predominantly in the liver and to a far lesser extent in the spleen, regardless of the size of the gold nanoparticles and the identity of the attached nanobody. We observed a striking difference in the distribution of radioisotope-labeled gold nanoparticles by changing the route of administration to intraperitoneal delivery. Significantly reduced accumulation in the liver and spleen was observed by intraperitoneal injection of nanoparticles. In the case of nanobody-modified gold nanoparticles injected intraperitoneally, prominent and persistent signals from the parathymic lymph nodes were observed in the PET/computed tomography images.

Effective in vitro delivery of paclitaxel by nanocargo of mesoporous polycaprolactone against triple negative breast cancer cells by minimalizing drug dose.

Among the breast cancers, triple negative breast cancer (TNBC) has relatively poor outcomes with a lower survival rate and personalised chemotherapy is the only option available for treatment. Currently in the biomedical domain, nanomaterials with porous morphology have revealed their tremendous possibilities to be used as a nanocarrier in treating cancer by offering void space to encapsulate/entrap biological agents. However, the development of nanocarrier-based targeted therapy with high therapeutic efficacy and fewer side effects to normal cells is always a challenge. Here, we have developed nanocargos based on biodegradable mesoporous PCL (polycaprolactone) of approx. diameter of 75 nm by template removal synthesis techniques. Succeeding the comparative analysis of the nanocarriers, the efficiencies of core shell PCL-mZnO (PZ) and mesoporous PCL (HPZ) to deliver paclitaxel (Taxol/T) into breast cancer cells, is investigated. We found that HPZ nanocapsules have less cytotoxicity and drug loading efficiency of about 600 µg mg-1. The Taxol-loaded nanoparticles (T-HPZ) have exhibited more cytotoxicity than Taxol alone treated cancer cells. Furthermore, T-HPZ treated MDA-MB231 cells are accumulated at G2/M phase of the cell cycle and eventually undergo apoptosis. In support of this, anchorage independent growth of MDA-MB231 cells are significantly inhibited by T-HPZ treatment. Together, our findings suggest that T-HPZ-based paclitaxel (Taxol/T) loaded nanoparticles provide a novel therapeutic option in the treatment of TNBC.

Mesoporous ZnO nanocapsules for the induction of enhanced antigen-specific immunological responses.

The application of nanotechnology in vaccinology has fuelled rapid advancement towards the design and development of nanovaccines. Nanoparticles have been found to enhance vaccine efficacy through the spatiotemporal orchestration of antigen delivery to secondary lymphoid organs and antigen-presentation by Antigen Presenting Cells (APCs) synchronized with stimulation of innate and adaptive immune responses. Metal based nanoparticles (MNPs) have been extensively engineered for the generation of nanovaccines owing to their intrinsic adjuvant-like properties and immunomodulatory functions. Furthermore, mesoporous nanocapsules of late have attracted researchers due to their precise size and exclusive capacity to encapsulate a wide range of biomolecules and their sustained release at the targeted sites. Herein, we have designed a novel mesoporous ZnO nanocapsule (mZnO) having a size of ∼12 nm with an average pore diameter of 2.5 nm, using a surfactant-free sonochemical method and investigated its immunomodulatory properties by using Ova loaded mZnO nanocapsules [mZnO(Ova)] in a mice model. Our findings show that mZnO(Ova) administration steered the enhanced expansion of antigen-specific T-cells and induction of IFN-γ producing effector CD4+ and CD8+ T-cells. Also, antigen-specific IgG levels were enriched in both the serum and lymph nodes of mZnO(Ova) immunized mice. Further, we noticed a substantial increase in serum IgG2a or IgG2b levels and IFN-γ secretion in Ova restimulated splenocytes from mZnO(Ova) immunized mice, indicating that mZnO(Ova) skew Th1 type immune response. Overall, the uniqueness of mZnO nanocapsules in terms of the defined particle to pore numbers ratio (maximum of three cavities per particle) allows loading antigens efficiently. Given these features in combination with its immunomodulatory characteristics reinforces the idea that mZnO could be used as an effective antigen-adjuvant platform for the development of novel nano-based vaccines against multiple diseases.

Designing idiosyncratic hmPCL-siRNA nanoformulated capsules for silencing and cancer therapy.

In this work, we have designed a siRNA-nanoformulation with mesoporous polycaprolactone (hmPCL) for silencing and cancer therapy. Average hollow core size of hmPCL nanocapsules used for nanoformulation is ~180 nm with shell thickness of 10-20 nm and mesopore size of ~5-10nm in diameter. Idiosyncratic capsules are biocompatible which has been confirmed with normal lymphocyte, K562 leukaemia cancer cells and on HepG2/EGFP cancer cells. In 1mg of hmPCL capsules up to 400 ng of siRNA can be loaded. This nanoformulation enables to tune the dose dependent delivery up to ~93.25% (373 ng) siRNA during therapy. hmPCL-siRNA nanoformulation mediated siRNA transfection on HepG2 cancer cells has been investigated and exhibited 32% silencing activity within 24h of post transfection. Obtained results directed us that the hmPCL-siRNA nanoformulation could be an efficient tool in siRNA mediated therapy for knocking down the infected cells. FROM THE CLINICAL EDITOR: siRNA could be used in cancer therapy if naked nucleic acid could be transported using a suitable carrier. In this article, the authors developed a nano-carrier system using mesoporous polycaprolactone (hmPCL) and showed its efficacy in knocking down cancer cells. This approach may open another way of gene therapy.