Biodegradable polymer possesses significant potential for applications in different fields, since flexibility gives rise to materials with great physical and mechanical property diversity. The poly-caprolactone (PCL) and chitosan derivatives (CS) have the ability to form scaffolds, which adhere to the surface of mesoporous silica nanoparticles (MSNs) and its porous networks. The novel characteristics of the developed PCL/MSNs and CS/MSNs, such as very low in vivo degradation rate, ordered pore network, uniform and tunable size and shape of the particles, high pore volume and surface area, non-toxicity, and biocompatibility, among others, are responsible for its favorable gene delivery device and makes this conjugation a very good biomaterial for this application. In the present study, we investigated the synthesis of silica nanoparticles MCM-41 covalently grafted with PCL and CS and their use as a potential small interfering RNA (siRNA) carrier. The physical–chemical and morphological characterizations, as well as the applicability of functionalized MSNs as platforms for gene delivery, were assessed. Our results confirmed that MSNs that were successfully functionalized with PCL and CS kept their typical morphology and pore arrangement. Furthermore, their surface modification was successfully held. In vitro biocompatibility and cytotoxicity assays suggest the ability of MSNs to support passive uptake and indicated the potential of this material as a gene delivery system for cervical cancer cells (HeLa).

Background: This study aimed the use of mesoporous silica under the naturally transformable Neisseria meningitidis, an important pathogen implicated in the genetic horizontal transfer of DNA causing a escape of the principal vaccination measures worldwide by the capsular switching process. This study verified the effects of mesoporous silica under N. meningitidis transformation specifically under the capsular replacement. Methods: we used three different mesoporous silica particles to verify their action in N. meningitis transformation frequency. Results: we verified the increase in the capsular gene replacement of this bacterium with the three mesoporous silica nanoparticles. Conclusion: the mesouporous silica particles were capable of increasing the capsule replacement frequency in N. meningitidis.

Since the possibility of silencing specific genes linked to retinal degeneration has become a reality with the use of small interfering RNAs (siRNAs), this technology has been widely studied to promote the treatment of several ocular diseases. Despite recent advances, the clinical success of gene silencing in the retina is significantly reduced by inherent anatomical and physiological ocular barriers, and new strategies are required to achieve intraocular therapeutic effectiveness. In this study, we developed lipoplexes, prepared with sodium alginate as an adjuvant and strategically coated with hyaluronic acid (HA-LIP), and investigated the potential neuroprotective effect of these systems in a retinal light damage model. Successful functionalization of the lipoplexes with hyaluronic acid was indicated in the dynamic light scattering and transmission electron microscopy results. Moreover, these HA-LIP nanoparticles were able to protect and deliver siRNA molecules targeting caspase-3 into the retina. After retinal degeneration induced by high light exposure, in vitro and in vivo quantitative reverse transcription-PCR (RT-qPCR) assays demonstrated significant inhibition of caspase-3 expression by HA-LIP. Furthermore, these systems were shown to be safe, as no evidence of retinal toxicity was observed by electroretinography, clinical evaluation or histology.