Citric acid functionalized silane coupling versus post-grafting strategy for dual pH and saline responsive delivery of cisplatin by Fe3O4/carboxyl functionalized mesoporous SiO2 hybrid nanoparticles: A-synthesis, physicochemical and biological characterization

A versatile theranostic magnetic polydopamine iron oxide NIR laser-responsive nanosystem containing doxorubicin for chemo-photothermal therapy of melanoma

Theranostics nanoparticles (NPs) have recently received much attention in cancer imaging and treatment. This study aimed to develop a multifunctional nanosystem for the targeted delivery of photothermal and chemotherapy agents. Fe3O4 NPs were modified with polydopamine, bovine serum albumin, and loaded with DOX via a thermal-cleavable Azo linker (Fe3O4@PDA@BSA-DOX). The size of Fe3O4@PDA@BSA NPs was approximately 98 nm under the desired conditions. Because of the ability of Fe3O4 and PDA to convert light into heat, the temperature of Fe3O4@PDA@BSA NPs increased to approximately 47 °C within 10 min when exposed to an 808 nm NIR laser with a power density of 1.5 W/cm2. The heat generated by the NIR laser leads to the breaking of AZO linker and drug release. In vivo and in vitro results demonstrated that prepared NPs under laser irradiation successfully eradicated tumor cells without any significant toxicity effect. Moreover, the Fe3O4@PDA@BSA NPs exhibited the potential to function as a contrasting agent. These NPs could accumulate in tumors with the help of an external magnet, resulting in a significant enhancement in the quality of magnetic resonance imaging (MRI). The prepared novel multifunctional NPs seem to be an efficient system for imaging and combination therapy in melanoma.

Ultrasound-mediated multifunctional magnetic microbubbles for drug delivery of celastrol in VX2 liver transplant tumors

Celastrol (CST) has positive pharmacological effects on various cancers, but clinical application is limited because of poor water solubility and systemic toxicity. Ferric oxide (Fe3O4) has a large specific surface area and can be functionalized by inorganic modification to form complex magnetic drug delivery systems. Herein, Fe3O4 was surface-modified with citric acid and polyethylene glycol (PEG) (via) the Mitsunobu reaction and then covalently bound to CST. Finally, magnetic microbubbles (MMBs) containing perfluoropropane (C3F8) and Fe3O4-PEG2K-CST particles were constructed with poly(lactic-co-glycolic acid) (PLGA) as the shell membrane. In vitro studies showed that ultrasound-mediated MMBs exhibited improved inhibition of VX2 cell proliferation compared to inhibition achieved using MMBs without ultrasound mediation, blank MMBs, or free CST. In ultrasound mode, MMBs have favorable imaging properties. After the application of a high mechanical index, MMBs collapse through the cavitation effect, releasing their internal Fe3O4-PEG2K-CST. The CST is then delivered to the tumor microenvironment under acidic conditions. In magnetic resonance imaging T2 mode, a specific hypointense signal was observed in the tumor area compared with that before treatment, whereas no significant change occurred in the signal intensity of the surrounding organs. After treatment, pathological examination of tumor-bearing rabbit tissues showed that iron elements accumulated in several apoptosis cells in the tumor area, with no apparent abnormalities found in other areas. Thus, ultrasound-mediated MMBs could significantly improve the drug uptake of solid tumors and inhibit tumor growth with favorable biological safety.

Gold Nanorods with Mesoporous Silica Shell: A Promising Platform for Cisplatin Delivery

The versatile combination of metal nanoparticles with chemotherapy agents makes designing multifunctional drug delivery systems attractive. In this work, we reported cisplatin's encapsulation and release profile using a mesoporous silica-coated gold nanorods system. Gold nanorods were synthesized by an acidic seed-mediated method in the presence of cetyltrimethylammonium bromide surfactant, and the silica-coated state was obtained by modified Stöber method. The silica shell was modified first with 3-aminopropyltriethoxysilane and then with succinic anhydride to obtain carboxylates groups to improve cisplatin encapsulation. Gold nanorods with an aspect ratio of 3.2 and silica shell thickness of 14.74 nm were obtained, and infrared spectroscopy and ζ potential studies corroborated surface modification with carboxylates groups. On the other hand, cisplatin was encapsulated under optimal conditions with an efficiency of ~58%, and it was released in a controlled manner over 96 h. Furthermore, acidic pH promoted a faster release of 72% cisplatin encapsulated compared to 51% in neutral pH.

Mesoporous silica nanoparticles as carrier to overcome bacterial drug resistant barriers

Antibiotic resistance has become a global threat to health due to abuse of antibiotics. Lots of existing antibiotics have lost their effect on drug resistant bacteria. Moreover, the discovery of novel antibiotics becomes more and more difficult. It is necessary to develop new strategies to fight against antibiotic resistance. Nano-drug delivery systems endow old antibiotics with new vitality to defeat the antibiotic resistant barrier by protecting antibiotics against hydrolysis, increasing uptake and circumventing efflux pump. Among them, mesoporous silica nanoparticles (MSNs) are one of the most extensively investigated as carrier of antibiotics due to large drug loading capability, tunable physicochemical characteristics, and biocompatibility. MSNs can improve the delivery of antibiotics to bacteria greatly by reducing size, modifying surface, and regulating shapes. Furthermore, MSNs hybridized metal ions or metal nanoparticles exert stronger antibacterial effect by controlling the release of metal ions or increasing active oxygen species. In addition, metal capped MSNs are also able to load antibiotics to exert synergistic antibacterial effect. This paper firstly reviewed the current application of various nanomaterials as antibacterial agents, and then focused on the MSNs including the introduction of MSNs and various approaches for improving antibacterial effect of MSNs.

Novel bioengineered MBenes for the treatment of Alzheimer's disease: An in-Sillico study

Alzheimer's disease is a neurodegenerative disease caused by the deposition and accumulation of amyloid-β (Aβ) peptides in the brain neurons. Current medications are not a definitive cure for this disease, but they can hamper the signs and symptoms of Alzheimer's disease. Therefore, prevention is the best way to deal with this disease. In this study, the novel structures based on MBenes (such as Cd₂B, Mo₂B, Cu₂B, and Ta₂B) are proposed to prevent amyloid-β accumulation in Alzheimer's disease. Regarding the remarkable MBene properties such as tunability, biocompatibility, and low manufacturing cost, the effect of these structures on amyloid-β deformation was explored using molecular dynamics simulation. To provide an atomic analysis of Beta-amyloid behavior in the presence of these structures, the compaction, contact area, and stability of Beta-amyloid were investigated. The results indicated the satisfactory performance of MBenes on the destabilization of amyloid-β structures. Moreover, given the higher interactions between Cd₂B and amyloid-β, the instability, compaction, and the contact area of amyloid-β particles were investigated in this complex. The findings confirmed Cd₂B as the best structure to prevent amyloid-β accumulation. The results of this investigation paved the way for the development of these structures as a medicinal agent to prevent Alzheimer's disease.

Fabrication and application of cisplatin-loaded mesoporous magnetic nanobiocomposite: a novel approach to smart cervical cancer chemotherapy

There are significant challenges in developing drug carriers for therapeutic perspective. We have investigated a novel nanocarrier system, based on combining functionalized magnetic nanocomposite with Metal–Organic Frameworks (MOFs). Magnetic nanoparticles modified using biocompatible copolymers may be suitable for delivering hydrophobic drugs, such as cisplatin. Furthermore, compared to polymeric nanocarriers, nanocomposite constructed from zeolitic imidazolate framework-8 (ZIF-8) have demonstrated better drug loading capacity, as well as excellent pH-triggered drug release. Cisplatin-encapsulated Fe3O4@SiO2-ZIF-8@N-Chit-FA has been evaluated to determine the antitumor effects of free cisplatin enhancement in cervical cancer cells. In order to increase the stability of the proposed nanocarrier in aqueous solutions, in addition to the density of functional groups, a nano-chitosan layer was coated on top of the magnetic nanocomposite. It was then added with cisplatin onto the surface of Fe3O4@SiO2-ZIF-8@N-Chit-FA to deliver anticancer treatment that could be targeted using a magnetic field. A mouse isograft model of TC1 cells was used to evaluate the in vivo tumor growth inhibition. In tumor-bearing mice, Fe3O4@SiO2-ZIF-8@N-Chit-FA-cisplatin was injected intraperitoneally, and the targeted delivery was amplified by an external magnet (10 mm by 10 mm, surface field strength 0.4 T) fixed over the tumor site. Based on in vivo results, cisplatin-Loaded Mesoporous Magnetic Nanobiocomposite inhibited the growth of cervical tumors (P < 0.001) through the induction of tumor necrosis (P < 0.05) when compared to cisplatin alone. With the application of an external magnetic field, the drug was demonstrated to be able to induce its effects on specific target areas. In summary, Fe3O4 @ SiO2-ZIF-8 @ N-Chit-FA nanocomposites have the potential to be implemented in targeted nanomedicine to deliver bio-functional molecules.

pH-responsive glycodendrimer as a new active targeting agent for doxorubicin delivery

The present study synthesized a new kind of pH-responsive active targeting glycodendrimer (ATGD) for doxorubicin delivery to cancerous cells. First, the glycodendrimer was synthesized based on the cultivation of chitosan dendrons on amine-functionalized, silica-grafted cellulose nanocrystals. Afterward, glycodendrimer was conjugated with folic acid to provide a folate receptor-targeting agent. The response surface method was employed to obtain the optimum conditions for the preparation of doxorubicin-loaded ATGD. The effect of doxorubicin/ATGD ratio, temperature, and pH on doxorubicin loading capacity was evaluated, and high loading capacity was achieved under optimized conditions. After determining doxorubicin release pattern at acidic and physiological pH, ATGD cytotoxicity was surveyed by MTT assay. Based on the results, the loading behavior of doxorubicin onto ATGD was in good agreement with monolayer-physisorption, and drug release was Fickian diffusion-controlled. ATGD could release the doxorubicin much more at acidic pH than physiological pH, corresponding to pH-responsive release behavior. Results of MTT assay confirmed the cytotoxicity of doxorubicin-loaded ATGD in cancer cells, while ATGD (without drug) was biocompatible with no tangible toxicity. These results suggested that ATGD has the potential for the treatment of cancer.

Sorafenib tosylate incorporation into mesoporous starch xerogel for in-situ micronization and oral bioavailability enhancement

Poorly water-soluble drugs like sorafenib tosylate (SFB) can be made more soluble and orally bioavailable using a biocompatible hydrophilic matrix yields amorphous or microcrystalline drugs with high stability and low recrystallization risk. Mesoporous starch (MPS) due to its edibility, biodegradability, high surface area, and confined pores. In this study, MPS, either alone or in combination with polyvinylpyrrolidone (PVP), was employed for improving SFB oral bioavailability. To this aim, MPS was prepared in three steps: gelatinization, solvent exchange, and vacuum drying, after which it was used to incorporate SFB at various ratios using the immersion/solvent evaporation technique. Nitrogen adsorption/desorption analysis, Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FE-SEM), powder X-ray diffraction (XRD) crystallography, and differential scanning calorimetry (DSC) were used to characterize SFB-loaded and drug-free samples, which confirmed the successful preparation of mesoporous structures with desirable uniform porosity, small pore size (about 5.3 nm), and specific surface area of about 24 m²/g. In-vitro dissolution testing revealed that the SFB dissolution rate increased substantially for the loaded MPS or MPS-PVP samples. Furthermore, when SFB was loaded in MPS-PVP, single-dose pharmacokinetics in rats confirmed an enhanced oral absorption kinetic. Therefore, impregnation of poorly soluble drugs such as SFB in the PVP-modified MPS excipient, which is constructed from a combination of mesoporous materials and a drug recrystallization inhibitor such as hydrophilic polymers, is proposed as a promising strategy for desirable enhancements in drug solubility, oral bioavailability, and efficacy.

Synthesis of Pore-Size-Tunable Mesoporous Silica Nanoparticles by Simultaneous Sol-Gel and Radical Polymerization to Enhance Silibinin Dissolution

BACKGROUND

Silibinin (SBN), a major active constituent of milk thistle seeds, exhibits numerous pharmacological activities. However, its oral bioavailability is low due to poor water solubility. This study aimed to develop a new synthetic approach for tuning the pore characteristics of mesoporous silica nanoparticles (MSNs) intended for the oral delivery of SBN. In addition, the effects of the pore diameter of MSNs on the loading capacity and the release profile of SBN were investigated.

METHODS

The present study was performed at Shiraz University of Medical Sciences, Shiraz, Iran, in 2019. This synthesis method shares the features of the simultaneous free-radical polymerization of methyl methacrylate and the sol-gel reaction of the silica precursor at the n-heptane/water interface. SBN was loaded onto MSNs, the in vitro release was determined, and the radical scavenging activities were compared between various pH values using the analysis of variance.

RESULTS

According to the Brunauer-Emmett-Teller protocol, the pore sizes were well-tuned in the range of 2 to 7 nm with a large specific surface area (600-1200 m²/g). Dynamic light scattering results showed that different volume ratios of n-heptane/water resulted in different sizes, ranging from 25 to 100 nm. Interestingly, high SBN loading (13% w/w) and the sustained release of the total drug over 12 hours were achieved in the phosphate buffer (pH=6.8). Moreover, the antioxidant activity of SBN was well preserved in acidic gastric pH.

CONCLUSION

Well-tuned pores of MSNs provided a proper substrate, and thus, enhanced SBN loading and oral dissolution and preserved its antioxidant activity. Nevertheless, further in vitro and in vivo investigations are needed.

Application or function of citric acid in drug delivery platforms

Nontoxic materials with natural origin are promising materials in the designing and preparation of the new drug delivery systems (DDSs). Today's, citric acid (CA) has attracted a great deal of attention because of its special features; green nature, biocompatibility, low price, biodegradability, and commercially available property. So, CA has been employed in the preparation of the various platforms to induce a suitable property on their structure. Recently, several research groups investigated the CA-based platforms in different forms like tablets, dendrimers, hyperbranched polymers, (co)polymer, hydrogels, and nanoparticles as efficient DDSs. By considering an increasing amount of published articles in this field, for the first time, in this review, an overview of the published works regarding CA applications in the design of various DDSs is presented with a detailed and insightful discussion.

Lipid, polymeric, inorganic-based drug delivery applications for platinum-based anticancer drugs

The three main FDA-approved platinum drugs in chemotherapy such as carboplatin, cisplatin, and oxaliplatin are extensively applied in cancer treatments. Although the clinical applications of platinum-based drugs are extremely effective, their toxicity profile restricts their extensive application. Therefore, recent studies focus on developing new platinum drug formulations, expanding the therapeutic aspect. In this sense, recent advances in the development of novel drug delivery carriers will help with the increase of drug stability and biodisponibility, concomitantly with the reduction of drug efflux and undesirable secondary toxic effects of platinum compounds. The present review describes the state of the art of platinum drugs with their biological effects, pre- and clinical studies, and novel drug delivery nanodevices based on lipids, polymers, and inorganic.

Hierarchical mesoporous zinc-imidazole dicarboxylic acid MOFs: Surfactant-directed synthesis, pH-responsive degradation, and drug delivery

The surfactant template-directed solvothermal method was applied in the synthesis of hierarchical mesoporous zinc-imidazolate derivative metal-organic framework (mesoMOF), which was then utilized for active loading of cisplatin (cis-Pt). To fabricate mesoMOF, various amounts of the surfactant (cetyltrimethylammonium bromide: 0.1-0.3 g) and linker (citric acid: 0.05-0.15 g) were added to the reaction mixture, which resulted in different particle sizes and morphologies. MesoMOF quality attributes such as Specific surface area (SSA), total porous volume, and Barrett-Joyner-Halenda (BJH) pore diameter were also determined. At the optimum reaction condition, mesoMOF with a high surface area (1859 m²/g), pore diameter (14.13 nm) and total pore volume (0.314 cm³/g) was attained. In the next step, cis-Pt was actively loaded in the mesoMOF with a high loading capacity (28% w/w), which was remarkably superior to the microporous MOF. Interestingly, in mildly acidic pH (5.5), mesoMOF underwent degradation, resulting in a rapid release of cis-Pt. Cell viability and apoptosis induction assays confirmed the superiority of the cis-Pt loaded mesoMOF over free drug in a resistant ovarian tumor cell line (A2780cp). Altogether, due to their tunable size and morphology, pH-responsiveness, and acceptable tolerability in mice, the mesoMOFs can be regarded as an anti-cancer drug delivery system.

Improved delivery system for celastrol-loaded magnetic Fe3O4/α-Fe2O3 heterogeneous nanorods: HIF-1α-related apoptotic effects on SMMC-7721 cell

Fe₃O₄/α-Fe₂O₃ heterogeneous nanorods were prepared by a rapid combustion method with α-FeOOH nanorods as precursors. Fe₃O₄/α-Fe₂O₃ heterogeneous nanorods with a saturation magnetization of 33.2 emu·g^-1 were obtained using 30 mL of absolute ethanol at a calcination temperature of 300 °C. Their average length was around 140 nm, and average diameter was about 20 nm. To improve the dispersion characteristics of the Fe₃O₄/α-Fe₂O₃ heterogeneous nanorods in aqueous solution, citric acid and PEG were applied to modify the nanorod surface via the Mitsunobu reaction. The results showed that the hydrodynamic size range of Fe₃O₄/α-Fe₂O₃/CA-PEG-celastrol was 250-500 nm, the surface potential was -15 mV, and the saturation magnetization was approximately 23 emu·g^-1. The drug loading capacity of Fe₃O₄/α-Fe₂O₃/CA-PEG was larger than the non-PEG modified version. Fe₃O₄/α-Fe₂O₃/CA-PEG-celastrol had slow-release characteristics and was sensitive to changes in pH. Application of a magnetic field significantly promoted the inhibition of SMMC-7721 human liver cancer cell growth after treatment with Fe₃O₄/α-Fe₂O₃/CA-PEG-celastrol. Celastrol and Fe₃O₄/α-Fe₂O₃/CA-PEG-celastrol increased the production of reactive oxygen species in SMMC-7721 cells and promoted apoptosis and apoptosis-related proteins (p53, Bax, Bcl-2) were also changed. In addition, the expression of hypoxia-inducible factor 1α (HIF-1α) was enhanced. We may conclude that celastrol-loaded magnetic Fe₃O₄/α-Fe₂O₃ heterogeneous nanorods may be applied in the chemotherapy of human cancer with good biocompatibility and delivery.

Green synthesis of iron-based nanoparticles using Chlorophytum comosum leaf extract: methyl orange dye degradation and antimicrobial properties

Nowadays, green synthesis methods have gained growing attention in nanotechnology owning to their versatile features including high efficiency, cost-effectiveness, and eco-friendliness. Here, the aqueous extract of Chlorophytum comosum leaf was applied for the preparation of iron nanoparticles (INPs) to obtain spherical and amorphous INPs with a particle size below 100 nm as confirmed by TEM. The synthesized INPs managed to eliminate methyl orange (MO) from the aqueous solution. The concentration of MO can be easily checked via ultraviolet-visible (UV-Vis) spectroscopy throughout the usage of INPs at the presence of H2O2. The synthesized INPs exhibited MO degradation efficiency of 77% after 6 h. Furthermore, the synthesized INPs exhibited antibacterial activity against both Gram-negative and Gram-positive bacteria. The prepared INPs have an impressive effect on Staphylococcus aureus at concentrations below 6 μg/ml. Overall, the synthesized INPs could considerably contribute to our combat against organic dyes and bacteria.

Progress in Mesoporous Silica Nanoparticles as Drug Delivery Agents for Cancer Treatment

Cancer treatment and therapy have made significant leaps and bounds in these past decades. However, there are still cases where surgical removal is impossible, metastases are challenging, and chemotherapy and radiotherapy pose severe side effects. Therefore, a need to find more effective and specific treatments still exists. One way is through the utilization of drug delivery agents (DDA) based on nanomaterials. In 2001, mesoporous silica nanoparticles (MSNs) were first used as DDA and have gained considerable attention in this field. The popularity of MSNs is due to their unique properties such as tunable particle and pore size, high surface area and pore volume, easy functionalization and surface modification, high stability and their capability to efficiently entrap cargo molecules. This review describes the latest advancement of MSNs as DDA for cancer treatment. We focus on the fabrication of MSNs, the challenges in DDA development and how MSNs address the problems through the development of smart DDA using MSNs. Besides that, MSNs have also been applied as a multifunctional DDA where they can serve in both the diagnostic and treatment of cancer. Overall, we argue MSNs provide a bright future for both the diagnosis and treatment of cancer.

Microneedle Arrays Combined with Nanomedicine Approaches for Transdermal Delivery of Therapeutics

Organic and inorganic nanoparticles (NPs) have shown promising outcomes in transdermal drug delivery. NPs can not only enhance the skin penetration of small/biomacromolecule therapeutic agents but can also impart control over drug release or target impaired tissue. Thanks to their unique optical, photothermal, and superparamagnetic features, NPs have been also utilized for the treatment of skin disorders, imaging, and biosensing applications. Despite the widespread transdermal applications of NPs, their delivery across the stratum corneum, which is the main skin barrier, has remained challenging. Microneedle array (MN) technology has recently revealed promising outcomes in the delivery of various formulations, especially NPs to deliver both hydrophilic and hydrophobic therapeutic agents. The present work reviews the advancements in the application of MNs and NPs for an effective transdermal delivery of a wide range of therapeutics in cancer chemotherapy and immunotherapy, photothermal and photodynamic therapy, peptide/protein vaccination, and the gene therapy of various diseases. In addition, this paper provides an overall insight on MNs' challenges and summarizes the recent achievements in clinical trials with future outlooks on the transdermal delivery of a wide range of nanomedicines.

GSH triggered intracellular aggregated-cisplatin-loaded iron oxide nanoparticles for overcoming cisplatin resistance in nasopharyngeal carcinoma

Platinum-based combined chemo-radiotherapy is the most commonly used approach against Nasopharyngeal carcinoma (NPC). However, off target effect and poor efficiency are the two main concerns regarding this approach. Therefore, it is an urgent need to explore novel therapeutic modalities to meet clinically standards. In this work we have established a new anti-cancer drug delivery system, composed of cisplatin (CDDP)-loaded magnetic iron oxide nanoparticles (Fe₃O₄), further functionalized with surface modification of folic acid (FA) and intracellular aggregation ability peptide (Cys(StBu)-Lys-CBT), named as (FA-MNP-CDDP-CBT). FA-MNP-CDDP-CBT was much more effective on the reversal of CDDP resistance with an average reduction in half maximal inhibitory concentration (IC 50) of 40.9% and 59.1% in HNE-1 cells and HNE-1/DDP resistant cells respectively compared to CDDP alone. Moreover, FA-MNP-CDDP-CBT had also shown a superior targeted uptake effect and higher ROS generation. Convincingly, we observed a remarkable increase in the apoptosis rate of NPC cells by using western blot and flow cytometry. Thus, this newly design nano-system provides a facile approach to enhance the antitumor activity by reducing the side effects of chemotherapy, minimizing systemic toxicity, and reversing CDDP treatment resistance, which could be proposed for NPC patients with primary or secondary chemo-resistance in the future.

Delivery of apigenin-loaded magnetic Fe2O3/Fe3O4@mSiO2 nanocomposites to A549 cells and their antitumor mechanism

This study introduces a mesoporous magnetic nano-system for the delivery of apigenin (API). A targeted therapeutic drug delivery system was prepared based on Fe₂O₃/Fe₃O₄@mSiO₂-HA nanocomposites. Magnetic Fe₂O₃/Fe₃O₄ heterogeneous nanoparticles were first prepared via the rapid-combustion process. The effects of solvent type, solvent volume, calcination temperature, and calcination time on the crystal size and magnetism of the Fe₂O₃/Fe₃O₄ heterogeneous nanoparticles were investigated. The mesoporous silica shell was deposited on the Fe₂O₃/Fe₃O₄ heterogeneous nanoparticles using an improved Stöber method. HA was exploited as the targeting ligand. The specific surface area of the Fe₂O₃/Fe₃O₄@mSiO₂ nanocomposites was 369.6 m²/g, which is 19 times higher than that of the magnetic Fe₂O₃/Fe₃O₄ heterogeneous nanoparticle cores. Drug release properties from the Fe₂O₃/Fe₃O₄@mSiO₂-HA nanocomposites were studied, and the result showed that API-loaded nano-system had sustained release effect. Prussian blue staining and electrochemical performance variation showed that an external magnetic field facilitated cell uptake of Fe₂O₃/Fe₃O₄@mSiO₂-HA nanocomposites. MTT assays showed that the cell inhibition effect of API-Fe₂O₃/Fe₃O₄@mSiO₂-HA was stronger than that of free API at the same drug dose under a magnetic field and Fe₂O₃/Fe₃O₄@mSiO₂-HA nanocomposites showed good biocompatibility. Fluorescence imaging, flow cytometry, western blot, reactive oxygen species (ROS), Superoxide dismutase (SOD) and malondialdehyde (MDA) kits verified that the enhanced therapeutic action was due to the promotion of apoptosis, lipid peroxidation, and ferroptosis. The magnetic nano-system (Fe₂O₃/Fe₃O₄@mSiO₂-HA) showed good magnetic targeting and active hyaluronic acid targeting, and has the potential to provide a targeted delivery platform for many antitumor drugs.

Fabrication of nanostructured mesoporous starch encapsulating soy-derived phytoestrogen (genistein) by well-tuned solvent exchange method

The present research was concerned with preparation of mesoporous starch (MPS) as a carrier for genistein, a model of poorly water-soluble phytoestrogen isoflavone; and exploration of the impact of different fabrication parameters on structural and loading properties. MPS is considered as a highly porous biomaterial which typically possesses nanometer-sized porous microstructure and low density, providing a large effective specific surface area (SSA) and hydrophilic surface to improve solubility, stability and bioavailability of poorly water-soluble active agents. To fabricate MPS, various concentrations (8-14% w/v) of starch from different sources (corn, potato and tapioca) was used for gel formation and the successive solvent exchange process was performed with use of various ethanol concentrations (40-70% v/v), which were then dried by different techniques (rotary vacuum evaporation, microwave and freeze drying). MPS quality attributes such as SSA, total porous volume, BJH pore diameter and swelling ratio were determined and effects of the fabrication parameters were investigated using L9-Taguchi orthogonal array design. The results indicate that second order polynomial regression models were well fitted for all response variables. Interestingly, the starch components greatly influenced physical properties of MPS. Also, the drying type and ethanol concentration altered significantly the model equations. The overall best fabrication condition (14% corn starch, 100% ethanol concentration in aging step and rotary vacuum drying) resulted in favorable MPS preparation with mean size of 105.4 nm and unimodal distribution. In the next step, genistein was encapsulated in MPS microstructure at different ratios, resulting in high loading capacity and efficiency (44.71% and 79.9%, respectively) at 1:1 weight ratio. Equilibrium adsorption isotherm of genistein was evaluated also by four different kinetics models including Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms. The experimental data were found to be fitted well to the Langmuir model (R2 = 0.989). According to the electron microscopy and XRD analysis, the degree of genistein crystallinity lowered remarkably after the impregnation in to MPS, indicating improved solubility. In-vitro release profile of genistein from MPS in the simulated gastrointestinal buffer solutions (pH 1.2 and 6.8) demonstrated that incorporating genistein into the MPS enhanced the dissolution rate compared with genistein powder. Release kinetic data were fitted to the Higuchi model (R2 = 0.98), indicating diffusion-controlled release mechanism. Altogether, well-tuned MPS fabrication method can be utilized for an efficient encapsulation and dissolution enhancement of poorly soluble phytochemicals, such as genistein.

Fabrication of oxidized bacterial cellulose by nitrogen dioxide in chloroform/cyclohexane as a highly loaded drug carrier for sustained release of cisplatin

Carboxylated bacterial cellulose (OBC) was fabricated by oxidation with nitrogen dioxide in chloroform/cyclohexane and employed as a carrier for sustained release of antitumor substance cisplatin (CDDP). The influence of removing water method, solvent used in the synthesis, concentration of N₂O₄, and duration of the oxidation on content of carboxyl groups in reaction products was established. Due to the possibility of nitrogen dioxide to penetrate into cellulose crystallites, the carboxyl group content of the OBC reaches high values up to 4 mmol/g. In vitro degradation of OBC was determined under simulated physiological conditions. The immobilization of CDDP on OBC was studied in detail. The initial burst release of the drug from the polymer was depressed. The cytotoxicity of CDDP-loaded OBC was evaluated with HeLa cells. The unique structure and properties of OBC make it a great candidate as drug delivery carrier.

Core-Shell Imidazoline-Functionalized Mesoporous Silica Superparamagnetic Hybrid Nanoparticles as a Potential Theranostic Agent for Controlled Delivery of Platinum(II) Compound

Introduction

As widely used chemotherapeutic agents, platinum compounds have several therapeutic challenges, such as drug resistance and adverse effects. Theranostic systems, macromolecular or colloidal therapeutics with companion diagnostics, not only address controlled drug delivery but also enable real-time monitoring of tumor sites.

Methods

Synthesis of magnetic mesoporous silica nanoparticles (MMSNs) was performed for dual magnetic resonance imaging and drug delivery. MMSN surfaces were modified by imidazoline groups (MMSN-Imi) for cisplatin (Cis-Pt) conjugation via free N-termini to achieve well-controlled drug-release kinetics. Cis-Pt adsorption isotherms and drug-release profile at pH 5 and 7.4 were investigated using inductively coupled plasma atomic emission spectroscopy.

Results

MMSN-Imi showed a specific surface area of 517.6 m² g⁻¹, mean pore diameter of 3.26 nm, and saturated magnetization of 53.63 emu/g. A relatively high r₂/r₁ relaxivity value was obtained for MMSN-Imi. The nanoparticles provided high Cis-Pt loading with acceptable loading capacity (~30% w:w). Sustained release of Cis-Pt under acidic conditions led to specific inhibitory effects on the growth of human epithelial ovarian carcinoma cells, determined using MTT assays. Dual acridine orange–propidium iodide staining was investigated, confirming induction of apoptosis and necrotic cell death.

Conclusion

MMSN-Imi exhibited potential for applications in cancer chemotherapy and combined imaging.