Drug release profiles of modified MCM-41 with superparamagnetic behavior correlated with the employed synthesis method

Morin loaded mesoporous molecular sieves as novel devices to the potential treatment of tumor pathologies

Morin is an antioxidant and anticancer flavonoid, extracted from natural sources, that may exert beneficial effects for several pathologies. Despite this, the administration of morin represents a challenge due to its low aqueous solubility. Mesoporous silica materials have emerged as biocompatible tools for drug delivery, as their pore size can be modulated for maximum surface area to volume ratio. In this contribution, we evaluate the ability of iron-modified mesoporous materials, for morin loading and controlled delivery. The SBA-15 and MCM-41 sieves were synthesized and modified with iron (metal content 4.02 and 6.27 % wt, respectivily). Characterization by transmission electron microscopy, XRD and UV-Vis revealed adequate pore size and agglomerates of very small metallic nanospecies (nanoclusters), without larger iron oxide nanoparticles. FT-IR spectra confirmed the presence of silanol groups in the solid hosts, which can interact with different groups present in morin molecules. SBA-15 materials were more efficient in terms of morin loading capacity (LC) due to their larger pore diameter. LC was more than 35% for SBA-15 materials when adsorptions studies were carried out with 9 mg of drug. Antioxidant activity were assayed by using DPPH test. Free iron materials presented a significate improvement as antioxidants after morin incorporation, reaching a scavenging activity of almost a 90%. On the other hand, in iron modified mesoporous materials, the presence of morin did not affect the scavenging activity. The results could be related with the formation of a complex between the flavonoid and the iron. Finally, biosafety studies using normal epithelial cells revealed that neither the loaded nor the unloaded materials exerted toxicity, even at doses of 1 mg/ml. These findings expand knowledge about mesoporous materials as suitable carriers of flavonoids with the aim of improving therapies for a wide range of pathologies.

Magnetic layered double hydroxides with carbamazepine for breast cancer treatment

Current cancer chemotherapy is associated with many side effects and, in some cases, drug resistance, which makes the search for new active molecules and drug delivery strategies imperative. Carbamazepine is an antiepileptic compound that has shown efficacy against breast cancer cell lines. In this study, it was incorporated into layered double hydroxide nanoclays, the percentage of drug loading was increased compared to previous research, and the clays were impregnated with magnetic Fe3O4 nanoparticles. The goal of the magnetic Fe3O4-impregnation was to direct the nanocomposites to the therapeutic target with an external magnetic field. The nanoclay-carbamazepine composites had a carbamazepine loading of 51 %, and the nanoclay-carbamazepine-nanoparticles had a drug loading of 13 % due to the addition of more ingredients. The structure of the composites was analyzed by X-ray diffraction and Scherrer equation, showing a layered double hydroxide organization with crystal sizes of 9-15 nm; from transmission electron microscopy, the final compounds showed a particle size of 97-158 nm, small enough for systemic circulation. In vibrating sample magnetization studies, the composites showed a superparamagnetic behavior with high magnetic saturation (9-17 emu/gr), which should allow a good material attraction by an external magnetic field located near the tumor. In vitro drug release studies were done in Franz cells and measured by UV/Vis spectrophotometry; they showed that carbamazepine release from the nanocomposites responds to the media pH: a good drug release at the lysosome pH and slow release at the blood pH. Finally, the efficacy was tested in vitro in MDA-MB-231 breast cancer cells, and the composites showed an enhanced efficacy in comparison with that produced by the free drug (96 % and 62 % of cell inhibition respectively). Carbamazepine administered with magnetic clays as a carrier is a promising treatment for breast cancer, and further studies should be done to measure the arrival time and the efficacy in vivo.

Insights of Platinum Drug Interaction with Spinel Magnetic Nanocomposites for Targeted Anti-Cancer Effect

In nanotherapeutics, gaining insight about the drug interaction with the pore architecture and surface functional groups of nanocarriers is crucial to aid in the development of targeted drug delivery. Manganese ferrite impregnated graphene oxide (MnFe₂O₄/GO) with a two-dimensional sheet and spherical silica with a three-dimensional interconnected porous structure (MnFe₂O₄/silica) were evaluated for cisplatin release and cytotoxic effects. Characterization studies revealed the presence of Mn²⁺ species with a variable spinel cubic phase and superparamagnetic effect. We used first principles calculations to study the physisorption of cisplatin on monodispersed silica and on single- and multi-layered GO. The binding energy of cisplatin on silica and single-layer GO was ~1.5 eV, while it was about double that value for the multilayer GO structure. Moreover, we treated MCF-7 (breast cancer cells) and HFF-1 (human foreskin fibroblast) with our nanocomposites and used the cell viability assay MTT. Both nanocomposites significantly reduced the cell viability. Pt⁴⁺ species of cisplatin on the spinel ferrite/silica nanocomposite had a better effect on the cytotoxic capability when compared to GO. The EC50 for MnFe₂O₄/silica/cisplatin and MnFe₂O₄/GO/cisplatin on MCF-7 was: 48.43 µg/mL and 85.36 µg/mL, respectively. The EC50 for the same conditions on HFF was: 102.92 µg/mL and 102.21 µg/mL, respectively. In addition, immunofluorescence images using c-caspase 3/7, and TEM analysis indicated that treating cells with these nanocomposites resulted in apoptosis as the major mechanism of cell death.

Synthesis and release behavior of layered double hydroxides-carbamazepine composites

Carbamazepine (CBZ) was incorporated into layered double hydroxides (LDH) to be used as a controlled drug system in solid tumors. CBZ has a formal charge of zero, so its incorporation in the anionic clay implies a challenge. Aiming to overcome this problem, CBZ was loaded into LDH with sodium cholate (SC), a surfactant with negative charge and, for comparison, without SC by the reconstruction method. Surprisingly, it was found that both resultant nanocomposites had similar CBZ encapsulation efficiency, around 75%, and the LDH-CBZ system without SC showed a better performance in relation to the release kinetics of CBZ in simulated body fluid (pH 7.4) and acetate buffer simulating the cellular cytoplasm (pH 4.8) than the system with SC. The CBZ dimensions were measured with Chem3D and, according to the basal spacing obtained from X-ray patterns, it can be arranged in the LDH-CBZ system as a monolayer with the long axis parallel to the LDH layers. Fourier transform infrared spectroscopy and solid state NMR measurements confirmed the presence of the drug, and thermogravimetric analyses showed an enhanced thermal stability for CBZ. These results have interesting implications since they increase the spectrum of LDH application as a controlled drug system to a large number of nonionic drugs, without the addition of other components.

Cisplatin-functionalized three-dimensional magnetic SBA-16 for treating breast cancer cells (MCF-7)

The engineering of multifunctional therapeutics in an integrated single platform is demonstrated using three-dimensional SBA-16 (S-16). 10 wt% iron oxide nanoparticles (Fe) were loaded into the cage type of cubic pores through enforced adsorption technique. Fe/S-16 is then functionalized with amine-based silane (A), polyacrylic acid (P) and cisplatin (Cp). The physicochemical textural analysis showed the formation of nano metal oxide distributions at pore walls of S-16 with magnetization of 2.39 emu/g. S-16 based nanoformulations showed high percentage of Cp adsorption (90%) and percentage cumulative release (60%). in vitro study of Fe/S-16-A-Cp showed high toxicity against breast cancer cell line MCF-7 and normal cell line Human foreskin fibroblast (HFF-1) compared to Fe/S-16 indicating cisplatin profusion inside the cells than free cisplatin. While skin fibroblast seems to be resistant to Fe/S-16-AP-Cp with very high LC₅₀ in compare to MCF-7. This indicates the unrelease of cisplatin in skin fibroblast after Fe/S-16-AP-Cp treatment due to effective encapsulation inside the cubic pores and core blockage due to pH-sensitive polyacrylic acid. Also, these treatments resulted in morphological changes in the cells such as DNA condensation and nuclear fragmentation.

Targeted therapeutic effect against the breast cancer cell line MCF-7 with a CuFe2O4/silica/cisplatin nanocomposite formulation

The combination of magnetic nanoparticles with a porous silica is a composite that has attracted significant attention for potential multifunctional theranostic applications. In this study, 30 wt % CuFe₂O₄ was impregnated into a matrix of monodispersed spherical hydrophilic silica (HYPS) nanoparticles through a simple dry impregnation technique. The chemotherapy drug cisplatin was loaded through electrostatic equilibrium adsorption over 24 h in normal saline solution. The presence of cubic spinel CuFe₂O₄ on HYPS was confirmed through powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR) and diffuse reflectance UV-vis spectroscopy (DR UV-vis) analysis. The HYPS particles showed a surface area of 170 m²/g, pore size of 8.3 nm and pore volume of 0.35 cm³/g. The cisplatin/CuFe₂O₄/HYPS nanoformulation showed the accumulation of copper ferrite nanoparticles on the surface and in the pores of HYPS with a surface area of 45 m²/g, pore size of 16 nm and pore volume of 0.18 cm³/g. Transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) mapping analysis showed the presence of homogeneous silica particles with nanoclusters of copper ferrite distributed on the HYPS support. Vibrating sample magnetometry (VSM) analysis of CuFe₂O₄/HYPS showed paramagnetic behavior with a saturated magnetization value of 7.65 emu/g. DRS UV-vis analysis revealed the functionalization of cisplatin in tetrahedral and octahedral coordination in the CuFe₂O₄/HYPS composite. Compared to other supports such as mesocellular foam and silicalite, the release of cisplatin using the dialysis membrane technique was found to be superior when CuFe₂O₄/HYPS was applied as the support. An in vitro experiment was conducted to determine the potential of CuFe₂O₄/HYPS as an anticancer agent against the human breast cancer cell line MCF-7. The results show that the nanoparticle formulation can effectively target cancerous cells and could be an effective tumor imaging guide and drug delivery system.

SPIONs/3D SiSBA-16 based Multifunctional Nanoformulation for target specific cisplatin release in colon and cervical cancer cell lines

Multifunctional nanomaterials can be used for dual applications: drug delivery as well as in bioimaging. In current study, we investigated potential use of silica based supports; 3D cage type SiSBA-16 (S-16), monodispersed hydrophilic spherical silica (HYPS) and mesocellular foam (MSU-F) for cisplatin (Cp) delivery. To obtain magnetic resonance characteristics, 10 wt% iron oxide was loaded through enforced adsorption technique. For pH stimuli responsive release of Cp, 10 wt%SPIONs/S-16 was functionalized with 3-(Aminopropyl)triethoxysilane (A) and poly acrylic acid (PAA) termed as 10 wt%SPIONs/S-16-A-Cp and 10 wt%SPIONs/S-16-APAA-Cp. By TEM analysis, the average diameter of the SPIONs was found to range between 10–60 nm. VSM analysis showed saturation magnetization over S-16, HYPS and MSU-F were in the following order: 10 wt%SPIONs/HYPS (4.08 emug⁻¹) > 10 wt%SPIONs /S-16 (2.39 emug⁻¹) > 10 wt%SPIONs/MSU-F (0.23 emug⁻¹). Cp release study using dialysis membrane in PBS solution over 10 wt%SPIONs/S-16 nanoformulations showed highest cumulative release (65%) than 10 wt%SPIONs/MSU-F-A-Cp (63%), 10 wt%SPIONs/HYPS-A-Cp (58%), and Cp-F127/S-16 (53%), respectively. 10 wt%SPIONs/S-16-A-Cp and 10 wt%SPIONs/S-16-APAA-Cp were evaluated for in vitro target anticancer efficiency in human cancer cell lines (colon cancer (HCT 116), cervical cancer (HeLa)) and normal cells (Human embryonic kidney cells (HEK293) using MTT and DAPI staining. 10 wt%SPIONs/S-16-A-Cp treated Hela and HCT116 cancerous cell lines showed significant control of cell growth, apoptotic activity and less cytotoxic effect as compared to Cp and 10 wt%SPIONs/S-16. Target specific Cp release in the cells shows that 10 wt%SPIONs/S-16-A-Cp can be easily upgraded for magnetic resonance imaging capability.