In vitro and in vivo evaluation of paclitaxel-loaded mesoporous silica nanoparticles with three pore sizes

Immunomodulatory potential of rapamycin-loaded mesoporous silica nanoparticles: pore size-dependent drug loading, release, and in vitro cellular responses

Rapamycin is a potent immunosuppressive drug that has been recently proposed for a wide range of applications beyond its current clinical use. For some of these proposed applications, encapsulation in nanoparticles is key to ensure therapeutic efficacy and safety. In this work, we evaluate the effect of pore size on mesoporous silica nanoparticles (MSN) as rapamycin nanocarriers. The successful preparation of MSN with 4 different pore sizes was confirmed by dynamic light scattering, zeta potential, transmission electron microscopy and N2 adsorption. In these materials, rapamycin loading was pore size-dependent, with smaller pore MSN exhibiting greater loading capacity. Release studies showed sustained drug release from all MSN types, with larger pore MSN presenting faster release kinetics. In vitro experiments using the murine dendritic cell (DC) line model DC2.4 showed that pore size influenced the biological performance of MSN. MSN with smaller pore sizes presented larger nanoparticle uptake by DC2.4 cells, but were also associated with slightly larger cytotoxicity. Further evaluation of DC2.4 cells incubated with rapamycin-loaded MSN also demonstrated a significant effect of MSN pore size on their immunological response. Notably, the combination of rapamycin-loaded MSN with an inflammatory stimulus (lipopolysaccharide, LPS) led to changes in the expression of DC activation markers (CD40 and CD83) and in the production of the proinflammatory cytokine TNF-α compared to LPS-treated DC without nanoparticles. Smaller-pored MSN induced more substantial reductions in CD40 expression while eliciting increased CD83 expression, indicating potential immunomodulatory effects. These findings highlight the critical role of MSN pore size in modulating rapamycin loading, release kinetics, cellular uptake, and subsequent immunomodulatory responses.

Silicon-containing nanomedicine and biomaterials: materials chemistry, multi-dimensional design, and biomedical application

The invention of silica-based bioactive glass in the late 1960s has sparked significant interest in exploring a wide range of silicon-containing biomaterials from the macroscale to the nanoscale. Over the past few decades, these biomaterials have been extensively explored for their potential in diverse biomedical applications, considering their remarkable bioactivity, excellent biocompatibility, facile surface functionalization, controllable synthesis, etc. However, to expedite the clinical translation and the unexpected utilization of silicon-composed nanomedicine and biomaterials, it is highly desirable to achieve a thorough comprehension of their characteristics and biological effects from an overall perspective. In this review, we provide a comprehensive discussion on the state-of-the-art progress of silicon-composed biomaterials, including their classification, characteristics, fabrication methods, and versatile biomedical applications. Additionally, we highlight the multi-dimensional design of both pure and hybrid silicon-composed nanomedicine and biomaterials and their intrinsic biological effects and interactions with biological systems. Their extensive biomedical applications span from drug delivery and bioimaging to therapeutic interventions and regenerative medicine, showcasing the significance of their rational design and fabrication to meet specific requirements and optimize their theranostic performance. Additionally, we offer insights into the future prospects and potential challenges regarding silicon-composed nanomedicine and biomaterials. By shedding light on these exciting research advances, we aspire to foster further progress in the biomedical field and drive the development of innovative silicon-composed nanomedicine and biomaterials with transformative applications in biomedicine.

The Exploitation of pH-Responsive Eudragit-Coated Mesoporous Silica Nanostructures in the Repurposing of Terbinafine Hydrochloride for Targeted Colon Cancer Inhibition: Design Optimization, In Vitro Characterization, and Cytotoxicity Assessment

Targeted drug delivery is achieving great success in cancer therapy due to its potential to deliver drugs directly to the action site. Terbinafine hydrochloride (TER) is a broad-spectrum anti-fungal drug that has been found to have some potential anti-tumor effects in the treatment of colon cancer. We aimed here to design and develop pH-sensitive Eudragit (Eud)-coated mesoporous silica nanostructures (MSNs) to control drug release in response to changes in pH. The diffusion-supported loading (DiSupLo) technique was applied for loading TER into the MSNs. The formulation was optimized by a D-optimal design, which permits the concurrent assessment of the influence of drug/MSN%, coat concentration, and MSN type on the drug entrapment efficiency (EE) and its release performance. The optimal formula displayed a high EE of 96.49%, minimizing the release in pH 1.2 to 16.15% and maximizing the release in pH 7.4 to 78.09%. The cytotoxicity of the optimal formula on the colon cancer cells HT-29 was higher than it was with TER alone by 2.8-fold. Apoptosis in cancer cells exposed to the optimum formula was boosted as compared to what it was with the plain TER by 1.2-fold and it was more efficient in arresting cells during the G0/G1 and S stages of the cell cycle. Accordingly, the repurposing of TER utilizing Eud/MSNs is a promising technique for targeted colon cancer therapy.

Polysorbate 80 surface modified PLGA nanoparticles: an in-vitro evaluation of cellular uptake and cytotoxicity on neuro-2a cells

AIM

Present study focuses on the development of P80 coated PLGA Nanoparticles loaded with drugs, paroxetine (P80-Par-PLGA-NPs) and clonidine (P80-CLD-PLGA-NPs) for in-vitro evaluation of Cellular Uptake & Cytotoxicity on Neuro-2a cells.

METHOD

P80-Par-PLGA-NPs and P80-CLD-PLGA-NPs were developed and characterised for zeta size, potential, PDI, EE%, DL%, TEM, SEM, FTIR, DSC, in-vitro release, cytotoxicity, histopathological and cell uptake studies using rhodamine loaded P80-NPs.

RESULT

Mean particle diameter of P80-Par-PLGA-NPs and P80-CLD-PLGA-NPs was 204; 182.7 nm, ZP of -21.8; -18.72 mV and 0.275; 0.341 PDI, respectively. TEM and SEM images revealed homogenous surface morphology. In-vitro drug release showed sustained and complete release in 72 h. Cell viability (>90%) at Cmax and no cytotoxicity in histopathology was observed. Significant higher uptake (96.9%) of P80-modified-NPS was observed as compared to unmodified-NPs (81%) (p < 0.05).

CONCLUSION

The finding clearly indicated a higher cell uptake of drugs via surface modified P80-coated PLGA-NPs as compared to unmodified particles.

Fabrication of a Dual-Targeted Liposome-Coated Mesoporous Silica Core-Shell Nanoassembly for Targeted Cancer Therapy

Nanoparticles have been suggested as drug-delivery systems for chemotherapeutic drugs to allow for controlled drug release profiles and selectivity to target cancer cells. In addition, nanoparticles can be used for the in situ generation and amplification of reactive oxygen species (ROS), which have been shown to be a promising strategy for cancer treatment. Thus, a targeted nanoscale drug-delivery platform could be used to synergistically improve cancer treatment by the action of chemotherapeutic drugs and ROS generation. Herein, we propose a promising chemotherapy strategy where the drug-loaded nanoparticles generate high doses of ROS together with the loaded ROS-generating chemotherapeutic drugs, which can damage the mitochondria and activate cell death, potentiating the therapeutic outcome in cancer therapy. In the present study, we have developed a dual-targeted drug-delivery nanoassembly consisting of a mesoporous silica core loaded with the chemotherapeutic, ROS-generating drug, paclitaxel (Px), and coated with a liposome layer for controlled drug release. Two different lung cancer-targeting ligands, folic acid and peptide GE11, were used to target the overexpressed nonsmall lung cancer receptors to create the final nanoassembly (MSN@Px) L-GF. Upon endocytosis by the cancer cells, the liposome layer was degraded by the intracellular lipases, and the drug was rapidly released at a rate of 65% within the first 20 h. In vitro studies confirmed that this nanoassembly was 8-fold more effective in cancer therapy compared to the free drug Px.

Application of Metal-Based Nanomaterials in In Vitro Diagnosis of Tumor Markers: Summary and Prospect

Cancer, which presents with high incidence and mortality rates, has become a significant health threat worldwide. However, there is currently no effective solution for rapid screening and high-quality treatment of early-stage cancer patients. Metal-based nanoparticles (MNPs), as a new type of compound with stable properties, convenient synthesis, high efficiency, and few adverse reactions, have become highly competitive tools for early cancer diagnosis. Nevertheless, challenges such as the difference between the microenvironment of detected markers and the real-life body fluids remain in achieving widespread clinical application of MNPs. This review provides a comprehensive review of the research progress made in the field of in vitro cancer diagnosis using metal-based nanoparticles. By delving into the characteristics and advantages of these materials, this paper aims to inspire and guide researchers towards fully exploiting the potential of metal-based nanoparticles in the early diagnosis and treatment of cancer.

Improved Muscle Regeneration into a Joint Prosthesis with Mechano-Growth Factor Loaded within Mesoporous Silica Combined with Carbon Nanotubes on a Porous Titanium Alloy

Total joint replacement (TJR) is widely applied as a promising treatment for the reconstruction of serious joint diseases but is usually characterized by critical loss of skeletal muscle attachment to metal joint prostheses, resulting in fibrous scar tissue formation and subsequent motor dysfunction. Tissue engineering technology may provide a potential strategy for skeletal muscle regeneration into metal joint prostheses. Here, a porous titanium (Ti) alloy scaffold coated with carbon nanotubes (CNTs) and mesoporous silica nanoparticles (MSNs) through electrophoretic deposition (EPD) was designed as a mechano-growth factor (MGF) carrier. This two-layered coating exhibits a nanostructured topology, excellent MGF loading, and prolonged release performance via covalent bonding to improve myoblast adhesion, proliferation and myogenic differentiation in porous Ti alloy scaffolds without cytotoxicity. The Akt/mTOR signaling pathway plays a key role in this process. Furthermore, in vivo studies show that the scaffold promotes the growth of muscle, rather than fibrotic tissue, into the porous Ti alloy structure and improves muscle-derived mechanical properties, the migration of satellite cells, and possibly immunomodulation. In summary, this nanomaterial-coated scaffold provides a practical biomaterial platform to regenerate periprosthetic muscle tissue and restore comparable motor function to that of the natural joint.

A review on the latest developments of mesoporous silica nanoparticles as a promising platform for diagnosis and treatment of cancer

Cancer is the second cause of human mortality after cardiovascular disease around the globe. Conventional cancer therapies are chemotherapy, radiation, and surgery. In fact, due to the lack of absolute specificity and high drug concentrations, early recognition and treatment of cancer with conventional approaches have become challenging issues in the world. To mitigate against the limitations of conventional cancer chemotherapy, nanomaterials have been developed. Nanomaterials exhibit particular properties that can overcome the drawbacks of conventional therapies such as lack of specificity, high drug concentrations, and adverse drug reactions. Among nanocarriers, mesoporous silica nanoparticles (MSNs) have gained increasing attention due to their well-defined pore size and structure, high surface area, good biocompatibility and biodegradability, ease of surface modification, and stable aqueous dispersions. This review highlights the current progress with the use of MSNs for the delivery of chemotherapeutic agents for the diagnosis and treatment of cancer. Various stimuli-responsive gatekeepers, which endow the MSNs with on-demand drug delivery, surface modification strategies for targeting purposes, and multifunctional MSNs utilized in drug delivery systems (DDSs) are also addressed. Also, the capability of MSNs as flexible imaging platforms is considered. In addition, physicochemical attributes of MSNs and their effects on cancer therapy with a particular focus on recent studies is emphasized. Moreover, major challenges to the use of MSNs for cancer therapy, biosafety and cytotoxicity aspects of MSNs are discussed.

Exploring the role of mesoporous silica nanoparticle in the development of novel drug delivery systems

The biocompatible nature of mesoporous silica nanoparticles (MSN) attracted researchers' attention to deliver therapeutic agents in the treatment of various diseases, where their porous nature, high drug loading efficiency, and suitability to functionalize with a specific ligand of MSN helped to obtain the desired outcome. The application of MSN has been extended to deliver small chemicals to large-sized peptides or proteins to fight against complex diseases. Recently, formulation researches with MSN have been progressed for various non-conventional drug delivery systems, including liposome, microsphere, oro-dispersible film, 3D-printed formulation, and microneedle. Low bulk density, retaining mesoporous structure during downstream processing, and lack of sufficient in vivo studies are some of the important issues towards the success of mesoporous silica-based advanced drug delivery systems. The present review has aimed to evaluate the application of MSN in advanced drug delivery systems to critically analyze the role of MSN in the respective formulation over other functionalized polymers. Finally, an outlook on the future direction of MSN-based advanced drug delivery systems has been drawn against the existing challenges with this platform.

The combination of nanotechnology and traditional Chinese medicine (TCM) inspires the modernization of TCM: review on nanotechnology in TCM-based drug delivery systems

Fast development of combination of nanotechnology with traditional Chinese medicine (TCM) broadens the field of application of TCM. Besides, it increases the research ideas and contributes to TCM modernization. As expected, TCM will be developed into the nanodrug delivery system by nanotechnology with careful design, which will enhance the medicinal value of TCM to cure and prevent disease based on benefits brought by nanometer scale. Here, formulations, relevant preparations methods, and characteristics of nano-TCM were introduced. In addition, the main excellent performances of nano-TCM were clearly elaborated. What is more, the review was intended to address the studies committed to application of nanotechnology in TCM over the years, including development of Chinese medicine active ingredients, complete TCM, and Chinese herbal compounds based on nanotechnology. Finally, this review discussed the safety of nano-TCM and presented future development trends in the way to realize the modernization of TCM. Overall, using the emerging nanotechnology in TCM is promising to promote progress of TCM in international platform. Recent researches on modernization of traditional Chinese medicine (TCM) urged by nanotechnology are introduced, and formulations, advantages, and applications of nano-TCM are reviewed to provide strong proofs.

An Update on Mesoporous Silica Nanoparticle Applications in Nanomedicine

The efficient and safe delivery of therapeutic drugs, proteins, and nucleic acids are essential for meaningful therapeutic benefits. The field of nanomedicine shows promising implications in the development of therapeutics by delivering diagnostic and therapeutic compounds. Nanomedicine development has led to significant advances in the design and engineering of nanocarrier systems with supra-molecular structures. Smart mesoporous silica nanoparticles (MSNs), with excellent biocompatibility, tunable physicochemical properties, and site-specific functionalization, offer efficient and high loading capacity as well as robust and targeted delivery of a variety of payloads in a controlled fashion. Such unique nanocarriers should have great potential for challenging biomedical applications, such as tissue engineering, bioimaging techniques, stem cell research, and cancer therapies. However, in vivo applications of these nanocarriers should be further validated before clinical translation. To this end, this review begins with a brief introduction of MSNs properties, targeted drug delivery, and controlled release with a particular emphasis on their most recent diagnostic and therapeutic applications.

Lamotrigine loaded PLGA nanoparticles intended for direct nose to brain delivery in epilepsy: pharmacokinetic, pharmacodynamic and scintigraphy study

The present study aimed to investigate the brain targeting efficacy of Lamotrigine (LTG) loaded PLGA nanoparticles (LTG-PNPs) upon intranasal administration. LTG-PNPs were fabricated through the emulsification-solvent evaporation technique and evaluated for % Entrapment efficiency, particle size, in-vitro release, surface morphology, crystallinity, ex-vivo permeation & thermal behaviour. Biodistribution, gamma scintigraphy, and pharmacodynamic studies were performed in BALB/c mice, New Zealand rabbits, and Wistar rats respectively. LTG-PNPs exhibited % EE 71%; particle size 170.0 nm; Polydispersity index 0.191; zeta potential -16.60 mV. LTG-PNPs exhibited a biphasic release pattern. Biodistribution and gamma scintigraphy studies proved a greater amount of LTG in the brain following intranasal delivery of LTG-PNPs in comparison to LTG-SOL. Pharmacodynamic studies demonstrated delayed seizure onset time with LTG-PNPs in comparison to LTG-SOL. Intranasal administration of LTG-PNPs provided prolonged release, higher bioavailability, and better brain targeting bypassing the BBB. The developed formulation could be administered as a once-a-day formulation that would reduce the dosing frequency; dose; dose-related side effects; cost of the therapy and would be beneficial in the management of epilepsy as compared to the LTG-SOL. However, the proof of concept generated through these studies needs to be further validated in higher animals and human volunteers.

Magnetically responsive, sorafenib loaded alginate microspheres for hepatocellular carcinoma treatment

This study aimed to develop sorafenib loaded magnetic microspheres for the treatment of hepatocellular carcinoma. To achieve this goal, superparamagnetic iron oxide nanoparticles (SPIONs) were synthesised and encapsulated in alginate microspheres together with an antineoplastic agent, sorafenib. In the study, firstly SPIONs were synthesised and characterised by dynamic light scattering, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Then, alginate-SPIONs microspheres were developed, and further characterised by electron spin resonance spectrometer and vibrating sample magnetometer. Besides the magnetic properties of SPIONs, alginate microspheres with SPIONs were also found to have magnetic properties. The potential use of microspheres in hyperthermia treatment was then investigated and an increase of about 4°C in the environment was found out. Drug release studies and cytotoxicity tests were performed after sorafenib was encapsulated into the magnetic microspheres. According to release studies, sorafenib has been released from microspheres for 8 h. Cytotoxicity tests showed that alginate-SPION-sorafenib microspheres were highly effective against cancerous cells and promising for cancer therapy.

Mesoporous silica nanoparticles: synthesis methods and their therapeutic use-recent advances

Mesoporous silica nanoparticles (MSNPs) are a particular example of innovative nanomaterials for the development of drug delivery systems. MSNPs have recently received more attention for biological and pharmaceutical applications due to their capability to deliver therapeutic agents. Due to their unique structure, they can function as an effective carrier for the delivery of therapeutic agents to mitigate diseases progress, reduce inflammatory responses and consequently improve cancer treatment. The potency of MSNPs for the diagnosis and management of various diseases has been studied. This literature review will take an in-depth look into the properties of various types of MSNPs (e.g. shape, particle and pore size, surface area, pore volume and surface functionalisation), and discuss their characteristics, in terms of cellular uptake, drug delivery and release. MSNPs will then be discussed in terms of their therapeutic applications (passive and active tumour targeting, theranostics, biosensing and immunostimulative), biocompatibility and safety issues. Also, emerging trends and expected future advancements of this carrier will be provided.

Formulation development of linagliptin solid lipid nanoparticles for oral bioavailability enhancement: role of P-gp inhibition

Linagliptin (LGP), a novel anti-diabetic drug, is a DPP-4 inhibitor used in the treatment of type II diabetes. One of the major disadvantages of LGP is its low oral bioavailability (29.5%) due to first-pass metabolism and P-gp efflux. In an attempt to increase the oral bioavailability, LGP solid lipid nanoparticles (LGP-SLNs) were developed with poloxamer 188 and Tween 80 as P-gp inhibitors. LGP-SLNs were formulated using palmitic acid, poloxamer 188 and Tween 80 as lipid, surfactant and co-surfactant, respectively, by hot homogenization ultrasonication method and optimized using 3² full factorial designs. Particle size, entrapment efficiency (%EE) and drug release at 24 h were evaluated as responses. An optimized batch of LGP-SLNs (L12) was evaluated for intestinal transport of LGP by conducting in situ single-pass intestinal perfusion (SPIP), everted gut sac and Caco-2 permeability study. The pharmacokinetic and pharmacodynamic evaluation of L12 was carried out in albino Wistar rats. The mean particle size, polydispersity index, zeta potential and %EE of L12 were found to be 225.96 ± 2.8 nm, 0.180 ± 0.034, - 5.4 ± 1.07 mV and 73.8 ± 1.73%, respectively. %CDR of 80.96 ± 3.13% was observed in 24 h. The permeability values of LGP-SLNs in the absorptive direction were 1.82-, 1.76- and 1.74-folds higher than LGP-solution (LGP-SOL) in SPIP, everted gut sac and Caco-2 permeability studies, respectively. LGP-SLNs exhibited relative bioavailability of 300% and better reduction in glucose levels in comparison with LGP-SOL in rats. The enhanced oral bioavailability exhibited by LGP-SLNs bioavailability may be due to P-gp efflux inhibition and lymphatic targeting. Improved bioabsorption can cause reduction in dose, dose-related side effects and frequency of administration. Thus, LGP-SLNs can be considered promising carriers for oral delivery but clinical studies are required to confirm the proof of concept.Graphical abstract.

PLGA nanoparticles for nose to brain delivery of Clonazepam: formulation, optimization by 32 Factorial design, in vitro and in vivo evaluation

BACKGROUND

Intranasal administration of biodegradable nanoparticles has been extensively studied for targeting the drug directly to CNS through olfactory or trigeminal route bypassing blood brain barrier.

OBJECTIVE

The objective of the present study was to optimize Clonazepam loaded PLGA nanoparticles (CLO-PNPs) by investigating the effect of process variables on the responses using 32 full factorial design.

METHODS

Effect of two independent factors-amount of PLGA and concentration of Poloxamer 188, were studied at low, medium and high levels on three dependent responses-%Entrapment efficiency, Particle size (nm) and %cumulative drug release at 24hr.

RESULTS

%EE, Particle size and %CDR at 24hr of optimized batch was 63.7%, 165.1 nm and 86.96% respectively. Nanoparticles were radiolabeled with 99mTc and biodistribution was investigated in BALB/c mice after intranasal & intravenous administrations. Significantly higher brain/blood uptake ratios and AUC values in brain following intranasal administration of CLO-PNPs indicated more effective brain targeting of CLO. Higher brain uptake of intranasal CLO-PNPs was confirmed by rabbit brain scintigraphy imaging. Histopathological study performed on goat nasal mucosa revealed no adverse response of nanoparticles. TEM image exhibited spherical shaped particles in nano range. DSC and XRD studies suggested Clonazepam encapsulation within PLGA matrix. The onset of occurrence of PTZ-induced seizures in rats was significantly delayed by intranasal nanoparticles as compared to intranasal & intravenous CLO-SOL.

CONCLUSION

This investigation exhibits rapid rate and higher extent of CLO transport in brain with intranasal CLO-PNPs suggesting a better option as compared to oral & parenteral route in management of acute status epilepticus.

Development of erianin-loaded dendritic mesoporous silica nanospheres with pro-apoptotic effects and enhanced topical delivery

Background

Psoriasis is a malignant skin disease characterized as keratinocyte hyperproliferation and aberrant differentiation. Our previous work reported that a bibenzyl compound, erianin, has a potent inhibitory effect on keratinocyte proliferation. To improve its poor water-solubility, increase anti- proliferation activity, and enhance the skin delivery, erianin loaded dendritic mesoporous silica nanospheres (E/DMSNs) were employed.

Results

In this work, DMSNs with pore size of 3.5 nm (DMSN₁) and 4.6 nm (DMSN₂) were fabricated and E/DMSNs showed pore-size-dependent, significantly stronger anti-proliferative and pro-apoptotic effect than free erianin on human immortalized keratinocyte (HaCaT) cells, resulting from higher cellular uptake efficiency. In addition, compared to free erianin, treatment with E/DMSNs was more effective in reducing mitochondrial membrane potential and increasing cytoplasmic calcium levels, which were accompanied by regulation of mitochondria and endoplasmic reticulum stress (ERS) pathway. Porcine skin was utilized in the ex vivo accumulation and permeation studies, and the results indicated higher drug retention and less drug penetration in the skin when administered as the E/DMSNs-loaded hydrogel compared to the erianin-loaded hydrogel.

Conlusions

This work not only illustrated the further mechanisms of erianin in anti-proliferation of HaCaT cells but also offer a strategy to enhance the efficiency of erianin and the capacity of skin delivery through the DMSNs drug delivery systems.

Rapid Self-Assembly of Polymer Nanoparticles for Synergistic Codelivery of Paclitaxel and Lapatinib via Flash NanoPrecipitation

Taxol, a formulation of paclitaxel (PTX), is one of the most widely used anticancer drugs, particularly for treating recurring ovarian carcinomas following surgery. Clinically, PTX is used in combination with other drugs such as lapatinib (LAP) to increase treatment efficacy. Delivering drug combinations with nanoparticles has the potential to improve chemotherapy outcomes. In this study, we use Flash NanoPrecipitation, a rapid, scalable process to encapsulate weakly hydrophobic drugs (logP < 6) PTX and LAP into polymer nanoparticles with a coordination complex of tannic acid and iron formed during the mixing process. We determine the formulation parameters required to achieve uniform nanoparticles and evaluate the drug release in vitro. The size of the resulting nanoparticles was stable at pH 7.4, facilitating sustained drug release via first-order Fickian diffusion. Encapsulating either PTX or LAP into nanoparticles increases drug potency (as indicated by the decrease in IC-50 concentration); we observe a 1500-fold increase in PTX potency and a six-fold increase in LAP potency. When PTX and LAP are co-loaded in the same nanoparticle, they have a synergistic effect that is greater than treating with two single-drug-loaded nanoparticles as the combination index is 0.23 compared to 0.40, respectively.

Enlarged Pore Size Chiral Mesoporous Silica Nanoparticles Loaded Poorly Water-Soluble Drug Perform Superior Delivery Effect

Large mesopores of chiral silica nanoparticles applied as drug carrier are worth studying. In this study, chiral mesoporous silica nanoparticles (CMSN) and enlarged chiral mesoporous silica nanoparticles (E-CMSN) with a particle size from 200 to 300 nm were synthesized. Fourier transform infrared spectrometer (FTIR), circular dichroism spectrum, scanning electron microscopy (SEM), transmission electron microscope (TEM), and nitrogen adsorption/desorption measurement were adopted to explore their characteristics. The results showed that the surface area, pore volume, and pore diameter of E-CMSN were higher than those of CMSN due to enlarged mesopores. Poorly water-soluble drug nimesulide (NMS) was taken as the model drug and loaded into carriers using adsorption method. After NMS was loaded into CMSN and E-CMSN, most crystalline NMS converted to amorphous phase and E-CMSN was superior. The anti-inflammatory pharmacodynamics and in vivo pharmacokinetics results were consistent with the wetting property and in vitro drug dissolution results, verifying that NMS/E-CMSN exhibited superior NMS delivery system based on its higher oral relative bioavailability and anti-inflammatory effect because its enlarge mesopores contributed to load and release more amorphous NMS. The minor variations in the synthesis process contributed to optimize the chiral nano-silica drug delivery system.

Pepper fragrant essential oil (PFEO) and functionalized MCM-41 nanoparticles: formation, characterization, and bactericidal activity

BACKGROUND

It is well known that plant essential oils have good antimicrobial activity. However, their strong volatility and intense odor limit their application. Mesoporous silica (MCM-41), a non-toxic mesoporous material with excellent loading capability, is a promising delivery system for different types of food ingredients in the food industry.

RESULTS

In this study, we first performed component analysis of pepper fragrant essential oil (PFEO) by gas chromatography - mass spectrometry (GC-MS), then the MCM-41 host was prepared, and the essential oil functionalized nanoparticles (EONs) were formed by embedding PFEO into mesoporous silica particles. Further analysis indicated that the particle size and zeta potential of EONs were 717 ± 13.38 nm and - 43.90 ± 0.67 mV, respectively. Transmission electron microscopy (TEM) images showed that EONs had an inerratic morphology and stable structure. The bactericidal activities of PFEO and EONs against Escherichia coli (E. coli), Salmonella enterica (S. enterica), Staphylococcus aureus (S. aureus) and Listeria monocytogenes (L. monocytogenes) were subsequently tested using the twofold dilution method. Results indicated that, after 48 h incubation, minimum bactericidal concentrations (MBC) of EONs used against gram-negative bacteria were decreased to a greater degree than those of PFEO, suggesting that nanoencapsulation by MCM-41 can improve antimicrobial activity. Atomic force microscopy (AFM) observation also confirmed that EONs showed a notable inhibitory effect against E. coli by disrupting cell membrane structure.

CONCLUSION

Pepper fragrant essential oil nanoencapsulation could be a very promising organic delivery system in food industry for antimicrobial activity enhancement. © 2019 Society of Chemical Industry.

New insights towards mesoporous silica nanoparticles as a technological platform for chemotherapeutic drugs delivery

Mesoporous silica nanoparticles (MSNs) displays interesting properties for biomedical applications such as high chemical stability, large surface area and tunable pores diameters and volumes, allowing the incorporation of large amounts of drugs, protecting them from deactivation and degradation processes acting as an excellent nanoplatform for drug delivery. However, the functional MSNs do not present the ability to transport the therapeutics without any leakage until reach the targeted cells causing side effects. On the other hand, the hydroxyls groups available on MSNs surface allows the conjugation of specific molecules which can binds to the overexpressed Enhanced Growth Factor Receptor (EGFR) in many tumors, representing a potential strategy for the cancer treatment. Beyond that, the targeting molecules conjugate onto mesoporous surface increase its cell internalization and act as gatekeepers blocking the mesopores controlling the drug release. In this context, multifunctional MSNs emerge as stimuli-responsive controlled drug delivery systems (CDDS) to overcome drawbacks as low internalization, premature release before to reach the region of interest, several side effects and low effectiveness of the current treatments. This review presents an overview of MSNs fabrication methods and its properties that affects drug delivery as well as stimuli-responsive CDDS for cancer treatment.

Development and evaluation of hollow mesoporous silica microspheres bearing on enhanced oral delivery of curcumin

The aim of this work is to develop curcumin-loaded hollow mesoporous silica microspheres (HMSMs@curcumin) to improve the poor oral bioavailability of curcumin. Hollow mesoporous silica microspheres (HMSMs) were synthesized in facile route using a hard template. HMSMs and HMSMs@curcumin were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption measurements, differential scanning calorimetry (DSC), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). In addition, to demonstrate the potential application of the HMSMs@curcumin, cytotoxicity, in vitro release behavior and in vivo pharmacokinetics of curcumin loaded in these HMSMs were investigated by using of Caco-2 cells and Sprague-Dawley (SD) rats, respectively. These mono-dispersed HMSMs exhibited high drug loading ratio and encapsulation efficiency due to the mesoporous shell and hollow core. The excellent characteristics of HMSMs such as mono-dispersed morphology, smooth surface, uniform, ordered and size-narrowing mesopores resulted in a good in vitro release profile of curcumin from HMSMs@curcumin. Moreover, an impressive improvement in the oral absorption of curcumin and prolonged systemic circulation time were achieved in the in vivo animal studies. In addition, the good biocompatibility of developed HMSMs with Caco-2 cells was confirmed based on the in vitro cytotoxicity assay. In conclusion, this system demonstrated a great potential for efficient delivery of curcumin in vitro and in vivo, suggesting a good prospect for its application in clinic for therapeutic drug delivery in future.

Strategies to Obtain Encapsulation and Controlled Release of Pentamidine in Mesoporous Silica Nanoparticles

Pentamidine (PTM), an antiprotozoal agent used in clinics as pentamidine isethionate salt (PTM-S), recently showed high potential also for the treatment of cancer and myotonic dystrophy type I. However, a severe limit to the systemic administration of PTM is represented by its nephrotoxicity, leading to the need for a system able to achieve a controlled release of the drug. In this study, mesoporous silica nanoparticles (MSNs) were employed for the first time to encapsulate PTM. PTM-S was first used for loading experiments into bare (MSN-OH) and aminopropyl, cyanopropyl and carboxypropyl-functionalized MSNs (MSN-NH₂, MSN-CN and MSN-COOH respectively) but it was not adequately loaded in any MSNs. The free base of PTM (PTM-B) was then obtained from PTM-S and successfully loaded into MSNs. Specifically, MSN-COOH exhibited the highest loading capacity. In vitro evaluation of PTM-B kinetic release from the different MSNs was carried out. An influence of the functional groups in slowing the release of the drug, when compared to bare MSNs was observed. Altogether, these results demonstrate that MSN-COOH could be a promising system to achieve a controlled release of PTM.

Dual-Porosity Hollow Carbon Spheres with Tunable Through-Holes for Multi-Guest Delivery

Dual-porosity hollow carbon spheres (DPHCs) with small mesopores (2-4 nm) and large through-holes (20-30 nm) in shells were successfully synthesized using colloidal silica as the template, small silica nanoparticles as nanomasks, and nontoxic dopamine as the carbon precursor followed by post-carbonization and etching. The synthesized DPHCs were further oxidized to be hydrophilic and then used to simultaneously deliver the protein bovine serum albumin (21 × 4 × 14 nm³) and the small molecule doxorubicin (<1 nm), which exhibited a high loading capacity of 689.4 and 1421.2 mg/g, respectively. The release of these two guest molecules can be controlled independently under the stimuli of heat and acidity. In vitro and in vivo experiments also proved that the DPHCs are promising for the co-delivery of multiple cargoes of different sizes.

Electrospun amorphous solid dispersions of poorly water-soluble drugs: A review

The development of oral dosage forms for poorly water-soluble active pharmaceutical ingredients (APIs) is a persistent challenge. A range of methods has been explored to address this issue, and amorphous solid dispersions (ASDs) have received increasing attention. ASDs are typically prepared by starting with a liquid precursor (a solution or melt) and applying energy for solidification. Many techniques can be used, with the emergence of electrospinning as a potent option in recent years. This method uses electrical energy to induce changes from liquid to solid. Through the direct applications of electrical energy, electrospinning can generate nanofiber-based ASDs from drug-loaded solutions, melts and melt-solutions. The technique can also be combined with other approaches using the application of mechanical, thermal or other energy sources. Electrospinning has numerous advantages over other approaches to produce ASDs. These advantages include extremely rapid drying speeds, ease of implentation, compatibility with a wide range of active ingredients (including those which are thermally labile), and the generation of products with large surface areas and high porosity. Furthermore, this technique exhibits the potential to create so-called 'fifth-generation' ASDs with nanostructured architectures, such as core/shell or Janus systems and their combinations. These advanced systems can improve dissolution behaviour and provide programmable drug release profiles. Additionally, the fiber components and their spatial distributions can be precisely controlled. Electrospun fiber-based ASDs can maintain an incorporated active ingredient in the amorphous physical form for prolonged periods of time because of their homogeneous drug distribution within the polymer matrix (typically they comprise solid solutions), and ability to inhibit molecular motion. These ASDs can be utilised to generate oral dosage forms for poorly water-soluble drugs, resulting in linear or multiple-phase release of one or more APIs. Electrospun ASDs can also be exploited as templates for manipulating molecular self-assembly, offering a bridge between ASDs and other types of dosage forms. This review addresses the development, advantages and pharmaceutical applications of electrospinning for producing polymeric ASDs. Material preparation and analysis procedures are considered. The mechanisms through which performance has been improved are also discussed.

Biodegradable Alginate-Chitosan Hollow Nanospheres for Codelivery of Doxorubicin and Paclitaxel for the Effect of Human Lung Cancer A549 Cells

A biodegradable alginate coated chitosan hollow nanosphere (ACHN) was prepared by a hard template method and used for codelivery of doxorubicin (DOX) and paclitaxel (PTX) to investigate the effect on human lung cancer A549 cells. PTX was loaded into the nanometer hollow structure of ACHN through adsorption method. DOX was coated on surface of ACHN through electrostatic interaction. Drug release studies exhibited a sustained-release effect. According to X-ray diffraction patterns (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT-IR) analysis, DOX structure in the loading samples (DOX-PTX-ACHN) was of amorphous state while PTX was microcrystalline. Cytotoxicity experiments showed ACHN was nontoxic as carrier material and the combination of DOX and PTX in DOX-PTX-ACHN exhibited a good inhibiting effect on cell proliferation. Cell uptake experiments demonstrated that DOX-PTX-ACHN accumulated in the cytoplasm. Degradation experiments illustrated that ACHN was a biodegradable material. In summary, these results clearly indicate that ACHN can be utilized as a potential biomaterial to transport multiple drugs to be used in combination therapy.

Mesoporous Silica Nanoparticles

Integration of nanotechnology and biomedicine has offered great opportunities for the development of nanoscaled therapeutic platforms. Amongst various nanocarriers, mesoporous silica nanoparticles (MSNs) is one of the most developed and promising inorganic materials-based drug delivery system for clinical translations due to their simple composition and nanoporous structure. MSNs possess unique structural features, for example, well-defined morphology, large surface areas, uniform size, controllable structure, flexible pore volume, tunable pore sizes, extraordinarily high loading efficiency, and excellent biocompatibility. Progress in structure control and functionalization may endow MSNs with functionalities that enable medical applications of these integrated nanoparticles such as molecularly targeted drug delivery, multicomponent synergistic therapy, in vivo imaging and therapeutic capability, on-demand/stimuli-responsive drug release, etc. In this chapter, the authors overview MSNs' characteristics and the scientific efforts developed till date involving drug delivery and biomedical applications.

Sustained-release study on Exenatide loaded into mesoporous silica nanoparticles: in vitro characterization and in vivo evaluation

BACKGROUND

Exenatide (EXT), the first glucagon-like peptide-1 receptor agonist, has been approved as an adjunctive therapy for patients with type 2 diabetes. Due to EXT's short half-life, EXT must be administrated by continuous subcutaneous (s.c.) injection twice daily. In previous studies, many studies on EXT loaded into polymer materials carriers for sustained release had been reported. However, these carriers have some defects, such as hydrophobicity, low surface energy, low mechanical strength, and poor chemical stability. Therefore, this study aims to develop a novel drug delivery system, which is EXT loaded into well-ordered hexagonal mesoporous silica structures (EXT-SBA-15), to control the sustainability of EXT.

METHODS

SBA-15 was prepared by hydrothermal method with uniform size. Morphology of SBA-15 was employed by transmission electron microscopy. The pore size of SBA-15 was characterized by N₂ adsorption-desorption isotherms. The in vitro drug release behavior and pharmacokinetics of EXT-SBA-15 were investigated. Furthermore, the blood glucose levels of diabetic mice were monitored after subcutaneous injection of EXT-Sol and EXT-SBA-15 to evaluate further the stable hypoglycemic effect of EXT-SBA-15.

RESULTS

EXT-SBA-15 showed a higher drug loading efficiency (15.2 ± 2.0%) and sustained-release features in vitro. In addition, pharmacokinetic studies revealed that the EXT-SBA-15 treatment group extended the half-life t _1/2(β) to 14.53 ± 0.70 h compared with that of the EXT solution (EXT-Sol) treatment group (0.60 ± 0.08 h) in vivo. Results of the pharmacodynamics study show that the EXT-SBA-15 treatment group had inhibited blood glucose levels below 20 mmol/L for 25 days, and the lowest blood glucose level was 13 mmol/L on the 10th day.

CONCLUSIONS

This study demonstrates that the EXT-SBA-15 delivery system can control the sustainability of EXT and contribute to improve EXT clinical use.

Effective delivery of volatile biocides employing mesoporous silicates for treating biofilms

Nanoparticulate delivery of biocides has the potential to decrease levels of exposure to non-target organisms, and miminize long-term exposure that can promote the development of resistance. Silica nanoparticles are an ideal vehicle since they are inert, biocompatible, biodegradable, and thermally and chemically stable. Encapsulation of biocides within nanoparticulates can improve their stability and longevity and maximize the biocidal potential of hydrophobic volatile compounds. Herein, we have shown that the plant secondary metabolites allyl isothiocyanate and cinnamaldehyde demonstrated increased antimicrobial activity against Escherichia coli in planktonic form, when packaged into mesoporous silica nanoparticles. Furthermore, the biocide-loaded nanoparticles showed activity against Pseudomonas aeruginosa biofilms that have inherent resistance to antimicrobial agents. The delivery platform can also be expanded to traditional biocides and other non-conventional antimicrobial agents.

Aptamer-Functionalized Nanoparticles as "Smart Bombs": The Unrealized Potential for Personalized Medicine and Targeted Cancer Treatment

Conventional delivery of chemotherapeutic agents leads to multiple systemic side effects and toxicity, limiting the doses that can be used. The development of targeted therapies to selectively deliver anti-cancer agents to tumor cells without damaging neighboring unaffected cells would lead to higher effective local doses and improved response rates. Aptamers are single-stranded oligonucleotides that bind to target molecules with both high affinity and high specificity. The high specificity exhibited by aptamers promotes localization and uptake by specific cell populations, such as tumor cells, and their conjugation to anti-cancer drugs has been explored for targeted therapy. Advancements in the development of polymeric nanoparticles allow anti-cancer drugs to be encapsulated in protective nonreactive shells for controlled drug delivery with reduced toxicity. The conjugation of aptamers to nanoparticle-based therapeutics may further enhance direct targeting and personalized medicine. Here we present how the combinatorial use of aptamer and nanoparticle technologies has the potential to develop "smart bombs" for targeted cancer treatment, highlighting recent pre-clinical studies demonstrating efficacy for the direct targeting to particular tumor cell populations. However, despite these pre-clinical promising results, there has been little progress in moving this technology to the bedside.

Reversing Cancer Multidrug Resistance in Xenograft Models via Orchestrating Multiple Actions of Functional Mesoporous Silica Nanoparticles

A multistimuli responsive drug delivery system (DDS) based on sulfhydryl and amino-cofunctionalized mesoporous silica nanoparticles (SH/NH2-MSNs) has been developed, in which the multifunctional hyaluronic acid (HA) derivatives were grafted onto the SH/NH2-MSNs by disulfide bonds for targeting delivery, controlling drug release and reversing multidrug resistance (MDR). The doxorubicin (Dox) loaded multifunctional HA derivatives modified mesoporous silica nanoparticles (Dox/HHS-MSNs) were enzyme and redox sensitive, which could respond to the intracellular stimuli of hyaluronidase (HAase) and glutathione (GSH) successively and prevent drug leakage before reaching the tumor tissues. The cellular uptake experiments showed that Dox/HHS-MSNs were vulnerable to be endocytosed into the Dox-resistant human breast adenocarcinoma (MCF-7/ADR) cells, efficiently realized the endolysosomal escape and remained in the cytoplasm. Because of orchestrating multiple actions above including active targeting, endolysosomal escape and efficient multilevel drug release, Dox/HHS-MSNs could induce the strongest apoptosis and cytotoxicity of MCF-7/ADR cells. Furthermore, a series of in vivo studies on MCF-7/ADR tumor-bearing xenograft mouse models demonstrated that Dox/HHS-MSNs possessed the enhanced tumor-targeting capacity and the best therapeutic efficacy to reverse cancer MDR.

Nanotherapeutics of PTEN Inhibitor with Mesoporous Silica Nanocarrier Effective for Axonal Outgrowth of Adult Neurons

Development of therapeutic strategies such as effective drug delivery is an urgent and yet unmet need for repair of damaged nervous systems. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) regulates axonal regrowth of central and peripheral nervous systems; its inhibition, meanwhile, facilitates axonal outgrowth of injured neurons. Here we show that nanotherapeutics based on mesoporous silica nanoparticles loading PTEN-inhibitor bisperoxovanadium (BpV) are effective for delivery of drug molecules and consequent improvement of axonal outgrowth. Mesoporous nanocarriers loaded BpV drug at large amount (27 μg per 1 mg of carrier), and released sustainably over 10 d. Nanocarrier-BpV treatment of primary neurons from the dorsal root ganglions (DRGs) of rats and mice at various concentrations induced them to actively take up the nanocomplexes with an uptake efficiency as high as 85%. The nanocomplex-administered neurons exhibited significantly enhanced axonal outgrowth compared with those treated with free-BpV drug. The expression of a series of proteins involved in PTEN inhibition and downstream signaling was substantially up-/down-regulated by the nanocarrier-BpV system. Injection of the nanocarriers into neural tissues (DRG, brain cortex, and spinal cord), moreover, demonstrated successful integration into neurons, glial cells, oligodendrocytes, and macrophages, suggesting the possible nanotherapeutics applications in vivo. Together, PTEN-inhibitor delivery via mesoporous nanocarriers can be considered a promising strategy for stimulating axonal regeneration in central and peripheral nervous systems.

Improving paclitaxel pharmacokinetics by using tumor-specific mesoporous silica nanoparticles with intraperitoneal delivery

Mesoporous silica nanoparticles (MSNs) containing paclitaxel for intraperitoneal (i.p.) delivery were developed to exploit the tumor specific accumulation of these nanocarriers after i.p. injection and the slow release of paclitaxel from the MSNs. A 3.5-fold increase in tumor cellular drug uptake was observed for the paclitaxel-loaded MSNs compared with free paclitaxel. An in vivo study using xenograft mice bearing peritoneal human pancreatic carcinoma MIA PaCa-2 demonstrated that the MSN-paclitaxel formulation, compared to free paclitaxel, exhibited a 3.2-fold increase in peritoneal cavity residence time, slower absorption into the systemic circulation with one third systemic exposure, but a 6.5-fold increase in peritoneal tumor accumulation. Tissue distribution imaging showed significantly greater accumulation of fluorescent MSNs in tumor tissues compared to other peritoneal tissues. In conclusion, intraperitoneal administration of drug-containing MSNs was effective at reducing systemic exposure and increasing the peritoneal tumor accumulation of paclitaxel.

The Architecture and Function of Monoclonal Antibody-Functionalized Mesoporous Silica Nanoparticles Loaded with Mifepristone: Repurposing Abortifacient for Cancer Metastatic Chemoprevention

The circulating tumor cells (CTCs) existing in cancer survivors are considered the root cause of cancer metastasis. To prevent the devastating metastasis cascade from initiation, we hypothesize that a biodegradable nanomaterial loaded with the abortifacient mifepristone (MIF) and conjugated with the epithelial cell adhesion molecule antibody (aEpCAM) may serve as a safe and effective cancer metastatic preventive agent by targeting CTCs and preventing their adhesion-invasion to vascular intima. It is demonstrated that MIF-loaded mesoporous silica nanoparticles (MSN) coated with aEpCAM (aE-MSN-M) can specifically target and bind colorectal cancer cells in either cell medium or blood through EpCAM recognition proven by quantitative flow cytometric detection and free aEpCAM competitive assay. The specific binding results in downregulation of the captured cells and drives them into G0/G1 phase primarily attributed to the effect of aEpCAM. The functional nanoparticles significantly inhibit the heteroadhesion between cancer cells and endothelial cells, suggesting the combined inhibition effects of aEpCAM and MIF on E-selectin and ICAM-1 expression. The functionalized nanoparticles circulate in mouse blood long enough to deliver MIF and inhibit lung metastasis. The present proof-of-concept study shows that the aE-MSN-M can prevent cancer metastasis by restraining CTC activity and their adhesion-invasion to vascular intima.