Structure-Property Relationship for Different Mesoporous Silica Nanoparticles and its Drug Delivery Applications: A Review

Preparation, Characterization, and Evaluation of the Anticancer Effect of Mesoporous Silica Nanoparticles Containing Rutin and Curcumin

AIMS AND OBJECTIVE

The aim of this study was the preparation of mesoporous silica nanoparticles co-loaded with rutin and curcumin (Rut-Cur-MSNs) and the assessment of its physicochemical properties as well as its cytotoxicity on the head and neck cancer cells (HN5). Besides, ROS generation of HN5 cells exposed to Rut-Cur-MSNs was evaluated. Several investigations showed that rutin and curcumin have potential effects as anticancer phytochemicals; however, their low aqueous solubility and poor bioavailability limited their applications. The assessment of physicochemical properties and anticancer effect of prepared nanoparticles was the objective of this study.

METHODS

The physicochemical properties of produced nanoparticles were evaluated. The toxicity of Rut-Cur-MSNs on HN5 cells was assessed. In addition, the ROS production in cells treated with Rut- Cur-MSNs was assessed compared to control untreated cells.

RESULTS

The results showed that Rut-Cur-MSNs have mesoporous structure, nanometer size and negative surface charge. The X-ray diffraction pattern showed that the prepared nanoparticles belong to the family of silicates named MCM-41. The cytotoxicity of Rut-Cur-MSNs at 24 h was significantly higher than that of rutin-loaded MSNs (Rut-MSNs) and curcumin-loaded MSNs (Cur-MSNs) (p<0.05).

CONCLUSION

The achieved results recommend that the prepared mesoporous silica nanoparticles containing rutin and curcumin can be a useful nanoformulation for the treatment of cancer. The produced nanomaterial in this study can be helpful for cancer therapy.

Recent Innovations of Mesoporous Silica Nanoparticles Combined with Photodynamic Therapy for Improving Cancer Treatment

Cancer is a global health burden and is one of the leading causes of death. Photodynamic therapy (PDT) is considered an alternative approach to conventional cancer treatment. PDT utilizes a light-sensitive compound, photosensitizers (PSs), light irradiation, and molecular oxygen (O2). This generates cytotoxic reactive oxygen species (ROS), which can trigger necrosis and/ or apoptosis, leading to cancer cell death in the intended tissues. Classical photosensitizers impose limitations that hinder their clinical applications, such as long-term skin photosensitivity, hydrophobic nature, nonspecific targeting, and toxic cumulative effects. Thus, nanotechnology emerged as an unorthodox solution for improving the hydrophilicity and targeting efficiency of PSs. Among nanocarriers, mesoporous silica nanoparticles (MSNs) have gained increasing attention due to their high surface area, defined pore size and structure, ease of surface modification, stable aqueous dispersions, good biocompatibility, and optical transparency, which are vital for PDT. The advancement of integrated MSNs/PDT has led to an inspiring multimodal nanosystem for effectively treating malignancies. This review gives an overview of the main components and mechanisms of the PDT process, the effect of PDT on tumor cells, and the most recent studies that reported the benefits of incorporating PSs into silica nanoparticles and integration with PDT against different cancer cells.

Controllable Synthesis of Hollow Silica Nanoparticles Using Layered Double Hydroxide Templates and Application for Thermal Insulation Coating

The innovative hollow silica nanoparticle (HSN) material possesses substantial potential for application in the insulation field. The size and shell thickness of HSN are crucial factors in determining their inherent properties, which, in turn, impact their applicability. This research presents a facile approach to synthesizing HSN in which sodium silicate (Na2SiO3) was utilized as the silica precursor that can be directly deposited onto layered double hydroxide (LDH) nanoparticles without the utilization of any surfactant. A subsequent acid treatment was used to eliminate the templates, resulting in the formation of an HSN devoid of mesopores in silica shells. By utilizing various sizes of LDH cores, obtainable via coprecipitation followed by hydrothermal treatment, we were capable of successfully synthesizing the hollow particles with adjustable diameters ranging from 50 to 200 nm. In addition, the shell thickness is varied from 6.8 to 22.5 nm by varying the silicate solution concentration. Results demonstrate that prepared HSNs have low thermal conductivity and high reflectance in the UV-vis-NIR range (averaging 82.1%). These findings suggest that HSN can be utilized as an effective inorganic filler in the formulation of reflective and thermally insulating coatings.

Fabrication, Characterization and Biomedical Evaluation of a Statistically Optimized Gelatin Scaffold Enriched with Co-Drugs Loaded into Controlled-Release Silica Nanoparticles

The current study focused on the fabrication of a well-designed, biocompatible, physically stable, non-irritating and highly porous gelatin scaffold loaded with controlled-release triamcinolone acetonide (TA) and econazole nitrate (EN) co-loaded into mesoporous silica nanoparticles (EN-TA-loaded MSNs) to provide a better long-lasting antifungal therapeutic effect with minimal unfavorable effects. Optimization of the MSNs-loaded scaffold was performed using central composite rotatable design (CCRD), where the effect of gelatin concentration (X1), plasticizer (X2) and freezing time (X3) on the entrapment of EN (Y1) and TA (Y2) and on the release of EN (Y3) and TA (Y4) from the scaffold were studied. The significant compatibility of all formulation ingredients with both drugs was established from XRD, DSC and FT-IR spectra analyses while SEM and zeta studies represented a very precise unvarying distribution of the loaded MSNs in the porous structure of the scaffold. The stability of the optimized scaffold was confirmed from zeta potential analysis (-16.20 mV), and it exhibited higher entrapment efficiency (94%) and the slower (34%) release of both drugs. During in vitro and in vivo antifungal studies against Candida albicans, the MSNs-loaded scaffold was comparatively superior in the eradication of fungal infections as a greater zone of inhibition was observed for the optimized scaffold (16.91 mm) as compared to the pure drugs suspension (14.10 mm). Similarly, the MSNs-loaded scaffold showed a decreased cytotoxicity because the cell survival rate in the scaffold presence was 89% while the cell survival rate was 85% in the case of the pure drugs, and the MSNs-loaded scaffold did not indicate any grade of erythema on the skin in comparison to the pure medicinal agents. Conclusively, the scaffold-loaded nanoparticles containing the combined therapy appear to possess a strong prospective for enhancing patients' adherence and therapy tolerance by yielding improved synergistic antifungal efficacy at a low dose with abridged toxicity and augmented wound-healing impact.

The Dawn of a New Era: Targeting the "Undruggables" with Antibody-Based Therapeutics

The high selectivity and affinity of antibodies toward their antigens have made them a highly valuable tool in disease therapy, diagnosis, and basic research. A plethora of chemical and genetic approaches have been devised to make antibodies accessible to more "undruggable" targets and equipped with new functions of illustrating or regulating biological processes more precisely. In this Review, in addition to introducing how naked antibodies and various antibody conjugates (such as antibody-drug conjugates, antibody-oligonucleotide conjugates, antibody-enzyme conjugates, etc.) work in therapeutic applications, special attention has been paid to how chemistry tools have helped to optimize the therapeutic outcome (i.e., with enhanced efficacy and reduced side effects) or facilitate the multifunctionalization of antibodies, with a focus on emerging fields such as targeted protein degradation, real-time live-cell imaging, catalytic labeling or decaging with spatiotemporal control as well as the engagement of antibodies inside cells. With advances in modern chemistry and biotechnology, well-designed antibodies and their derivatives via size miniaturization or multifunctionalization together with efficient delivery systems have emerged, which have gradually improved our understanding of important biological processes and paved the way to pursue novel targets for potential treatments of various diseases.

Surface-Modified Silica Hydrogels for the Programmable Release of Bisphosphonate Anti-Osteoporosis Drugs: The Case of Etidronate

Bisphosphonate drugs constitute the primary treatment for bone diseases such as Paget's disease and osteoporosis. Despite their effectiveness, they also exhibit severe drawbacks, such as rapid excretion and limited oral bioavailability. High doses are usually administered to counterbalance these drawbacks. Subsequently, side effects are triggered, such as osteonecrosis of the lower jaw and esophageal cancer. Controlled drug release systems may be viable candidates to overcome those issues. Herein, we present novel functionalized silica-based hydrogels loaded with the osteoporosis drug etidronate (1,1-hydroxyethylidene-diphosphonate) used to control the release profile of the drug. Various methodologies were evaluated to control the initial release rate and the final released concentration of the drug. These included the gel density, by systematically increasing the initial concentration of silicate used to prepare the hydrogels, the presence of metal cations (Ca²⁺ and Cu²⁺), and the internal surface functionalization of the gel with silane-based grafting agents (with anionic, cationic, and neutral groups). This study also contributes to our continuous effort to develop new a priori programmable drug-loaded gels for the controlled release of osteoporosis drugs.

Enhanced and Extended Ophthalmic Drug Delivery by pH-Triggered Drug-Eluting Contact Lenses with Large-Pore Mesoporous Silica Nanoparticles

Drug-eluting contact lenses (DCLs) have attracted considerable attention as potential therapeutic ophthalmic drug delivery devices. In this study, we propose, fabricate, and investigate pH-triggered DCLs that are combined with large-pore mesoporous silica nanoparticles (LPMSNs). Compared to reference DCLs, LPMSN-laden DCLs can prolong the residence time of glaucoma drugs in an artificial lacrimal fluid (ALF) environment at pH 7.4. Additionally, LPMSN-laden DCLs do not require drug preloading and are compatible with current contact lens manufacturing processes. LPMSN-laden DCLs soaked at pH 6.5 exhibit better drug loading than reference DCLs due to their specific adsorption. The sustained and extended release of glaucoma drugs by LPMSN-laden DCLs was successfully monitored in ALF, and the drug release mechanism was further explained. We also evaluated the cytotoxicity of LPMSN-laden DCLs, and qualitative and quantitative results showed no cytotoxicity. Our experimental results demonstrate that LPMSNs are excellent nanocarriers that have the potential to be used as safe and stable nanocarriers for the delivery of glaucoma drugs or other drugs. pH-triggered LPMSN-laden DCLs can significantly improve drug loading efficiency and control prolonged drug release, indicating that they have great potential for future biomedical applications.

Advances of Mussel-Inspired Nanocomposite Hydrogels in Biomedical Applications

Hydrogels, with 3D hydrophilic polymer networks and excellent biocompatibilities, have emerged as promising biomaterial candidates to mimic the structure and properties of biological tissues. The incorporation of nanomaterials into a hydrogel matrix can tailor the functions of the nanocomposite hydrogels to meet the requirements for different biomedical applications. However, most nanomaterials show poor dispersion in water, which limits their integration into the hydrophilic hydrogel network. Mussel-inspired chemistry provides a mild and biocompatible approach in material surface engineering due to the high reactivity and universal adhesive property of catechol groups. In order to attract more attention to mussel-inspired nanocomposite hydrogels, and to promote the research work on mussel-inspired nanocomposite hydrogels, we have reviewed the recent advances in the preparation of mussel-inspired nanocomposite hydrogels using a variety of nanomaterials with different forms (nanoparticles, nanorods, nanofibers, nanosheets). We give an overview of each nanomaterial modified or hybridized by catechol or polyphenol groups based on mussel-inspired chemistry, and the performances of the nanocomposite hydrogel after the nanomaterial's incorporation. We also highlight the use of each nanocomposite hydrogel for various biomedical applications, including drug delivery, bioelectronics, wearable/implantable biosensors, tumor therapy, and tissue repair. Finally, the challenges and future research direction in designing mussel-inspired nanocomposite hydrogels are discussed.

Mesoporous Materials Make Hydrogels More Powerful in Biomedicine

Scientists have been attempting to improve the properties of mesoporous materials and expand their application since the 1990s, and the combination with hydrogels, macromolecular biological materials, is one of the research focuses currently. Uniform mesoporous structure, high specific surface area, good biocompatibility, and biodegradability make the combined use of mesoporous materials more suitable for the sustained release of loaded drugs than single hydrogels. As a joint result, they can achieve tumor targeting, tumor environment stimulation responsiveness, and multiple therapeutic platforms such as photothermal therapy and photodynamic therapy. Due to the photothermal conversion ability, mesoporous materials can significantly improve the antibacterial ability of hydrogels and offer a novel photocatalytic antibacterial mode. In bone repair systems, mesoporous materials remarkably strengthen the mineralization and mechanical properties of hydrogels, aside from being used as drug carriers to load and release various bioactivators to promote osteogenesis. In hemostasis, mesoporous materials greatly elevate the water absorption rate of hydrogels, enhance the mechanical strength of the blood clot, and dramatically shorten the bleeding time. As for wound healing and tissue regeneration, incorporating mesoporous materials can be promising for enhancing vessel formation and cell proliferation of hydrogels. In this paper, we introduce the classification and preparation methods of mesoporous material-loaded composite hydrogels and highlight the applications of composite hydrogels in drug delivery, tumor therapy, antibacterial treatment, osteogenesis, hemostasis, and wound healing. We also summarize the latest research progress and point out future research directions. After searching, no research reporting these contents was found.

Increasing Bioavailability of Trans-Ferulic Acid by Encapsulation in Functionalized Mesoporous Silica

Two types of mesoporous materials, MCM-41 and MCM-48, were functionalized by the soft-template method using (3-aminopropyl)triethoxysilane (APTES) as a modifying agent. The obtained mesoporous silica materials were loaded with trans-ferulic acid (FA). In order to establish the morphology and structure of mesoporous materials, a series of specific techniques were used such as: X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer-Emmet-Teller (BET), Fourier Transform Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). We monitored the in vitro release of the loaded FA at two different pH values, by using simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). Additionally, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Candida albicans ATCC 10231 were used to evaluate the antimicrobial activity of FA loaded mesoporous silica materials. In conclusion such functionalized mesoporous materials can be employed as controlled release systems for polyphenols extracted from natural sources.

Biomimetic camouflaged nanoparticles with selective cellular internalization and migration competences

In the last few years, nanotechnology has revolutionized the potential treatment of different diseases. However, the use of nanoparticles for drug delivery might be limited by their immune clearance, poor biocompatibility and systemic immunotoxicity. Hypotheses for overcoming rejection from the body and increasing their biocompatibility include coating nanoparticles with cell membranes. Additionally, source cell-specific targeting has been reported when coating nanoparticles with tumor cells membranes. Here we show that coating mesoporous silica nanoparticles with membranes derived from preosteoblastic cells could be employed to develop potential treatments of certain bone diseases. These nanoparticles were selected because of their well-established drug delivery features. On the other hand MC3T3-E1 cells were selected because of their systemic migration capabilities towards bone defects. The coating process was here optimized ensuring their drug loading and delivery features. More importantly, our results demonstrated how camouflaged nanocarriers presented cellular selectivity and migration capability towards the preosteoblastic source cells, which might constitute the inspiration for future bone disease treatments. STATEMENT OF SIGNIFICANCE: This work presents a new nanoparticle formulation for drug delivery able to selectively target certain cells. This approach is based on Mesoporous Silica Nanoparticles coated with cell membranes to overcome the potential rejection from the body and increase their biocompatibility prolonging their circulation time. We have employed membranes derived from preosteoblastic cells for the potential treatment of certain bone diseases. Those cells have shown systemic migration capabilities towards bone defects. The coating process was optimized and their appropriate drug loading and releasing abilities were confirmed. The important novelty of this work is that the camouflaged nanocarriers presented cellular selectivity and migration capability towards the preosteoblastic source cells, which might constitute the inspiration for future bone disease treatments.

The role of cell membrane-coated nanoparticles as a novel treatment approach in glioblastoma

Glioblastoma multiform (GBM) is the most prevalent and deadliest primary brain malignancy in adults, whose median survival rate does not exceed 15 months after diagnosis. The conventional treatment of GBM, including maximal safe surgery followed by chemotherapy and radiotherapy, usually cannot lead to notable improvements in the disease prognosis and the tumor always recurs. Many GBM characteristics make its treatment challenging. The most important ones are the impermeability of the blood-brain barrier (BBB), preventing chemotherapeutic drugs from reaching in adequate amounts to the tumor site, intratumoral heterogeneity, and roles of glioblastoma stem cells (GSCs). To overcome these barriers, the recently-developed drug-carrying approach using nanoparticles (NPs) may play a significant role. NPs are tiny particles, usually less than 100 nm showing various diagnostic and therapeutic medical applications. In this regard, cell membrane (CM)-coated NPs demonstrated several promising effects in GBM in pre-clinical studies. They benefit from fewer adverse effects due to their specific targeting of tumor cells, biocompatibility because of their CM surfaces, prolonged half-life, easy penetrating of the BBB, and escaping from the immune reaction, making them an attractive option for GBM treatment. To date, CM-coated NPs have been applied to enhance the effectiveness of major therapeutic approaches in GBM treatment, including chemotherapy, immunotherapy, gene therapy, and photo-based therapies. Despite the promising results in pre-clinical studies regarding the effectiveness of CM-coated NPs in GBM, significant barriers like high expenses, complex preparation processes, and unknown long-term effects still hinder its mass production for the clinic. In this regard, the current study aims to provide an overview of different characteristics of CM-coated NPs and comprehensively investigate their application as a novel treatment approach in GBM.

Three Different Interaction Patterns between MCM-41 and Proteins

As one of the most studied mesoporous silica nanoparticles (MSNs) in drug delivery systems, Mobil Composition of Matter No. 41 (MCM-41) possesses unique properties including perfect channel architecture, excellent load capacity, and good biocompatibility. However, the applications of MCM-41 nanoparticles in drug delivery have not yet been industrialized, due to the interaction between MCM-41 and biomolecules (especially proteins) that affect their in vivo behaviors after dosing. To investigate the interactions between MCM-41 and proteins, this study selected bovine serum albumin (BSA), lysozyme (Lyso), and bovine hemoglobin (BHb) as model proteins and characterized the ultraviolet-visible, fluorescence, circular dichroism spectra and the protein adsorption of MCM-41-protein complex. The UV-Vis spectra exhibited the different absorption increment degrees of three proteins. The fluorescence spectra showed that the fluorescence intensity of proteins changed by different trends. The CD spectra indicated that the secondary structure changes were ranked as BSA > Lyso > BHb, which is consistent with the protein’s adsorption capability on MCM-41. It was shown that there were three different patterns of MCM-41-proteins interactions. The hydrophilic and low-charged BSA followed the strong interaction pattern, the hydrophilic but heavily charged Lyso followed the moderate interaction pattern, and the hydrophobic BHb followed the weak interaction pattern. Different interaction patterns would lead to different effects on the structural properties of proteins, the surface chemistry of MCM-41, and the absorption capability of proteins on MCM-41. We believe our study will provide a better insight into the application of MCM-41 nanoparticles in drug delivery systems.

Interactions of Antibacterial Naphthoquinones with Mesoporous Silica Surfaces: A Physicochemical and Theoretical Approach

1,4-naftoquinone (NQ) molecules have been extensively evaluated as potent antibacterial compounds; however, their use is limited, since they have low water solubility and exhibit toxicities in healthy eukaryotic cells. A possible path to overcoming these challenges is the use of particulate vehicles, such as SBA-15, which is a biocompatible and biodegradable mesoporous silica material, that may enhance drug delivery and decrease dosages. In this work, an isotherm model-based adsorption of three NQs into SBA-15 microparticles was evaluated. Interactions between NQs and SBA-15 microparticles were modeled at the B3LYP/6-31+G(d,p) level of theory to understand the nature of such interactions. The results demonstrated that the adsorption of NQ, 2NQ, and 5NQ into SBA-15 fit the Freundlich adsorption model. According to theorical studies, physisorption is mediated by hydrogen bonds, while the most stable interactions occur between the carbonyl group of NQ and silica surfaces. Both experimental and theoretical results contribute to a deeper understanding of the use of SBA-15 or similar particles as nanovehicles in such a way that NQs can be modified in carbonyl or C3 to enhance adsorptions. The theoretical and experimental results were in accordance and contribute to a deeper understanding of how interactions between NQ-type molecules and SiO₂ materials occur.

Effect of chain length on the cytotoxic activity of (alkyl-ω-ol)triphenyltin(IV) loaded into SBA-15 nanostructured silica and in vivo study of SBA-15~Cl|Ph3Sn(CH2)8OH

A series of nanostructured SBA-15-based materials functionalized with the tetraorganotin(IV) metallodrugs Ph₃Sn(CH₂)_nOH (n = 3, 4, 6, 8 and 11) are synthesized and structurally characterized by different techniques used in solid-state chemistry. The cytotoxicity of both the organotin(IV) compounds and the tin-functionalized SBA-15 materials are studied against different cancer cell lines observing that the materials have similar cytotoxic activity in comparison with the free organotin compounds in terms of mass. However, considering that the percentage of active metal compound loaded into material is low, the utilization of mesoporous silica as drug vehicle clearly improves the cytotoxic effectiveness of metal-based drugs against cancer cells. One of the most potent between all tested systems is material SBA-15~Cl|Ph₃Sn(CH₂)₈OH. Its cytotoxicity seems to come from additional mechanisms apart from apoptosis provoking cell reprogram in B16 melanoma into more mature and less aggressive phenotype. Moderated production of ROS/RNS is probably in the background of observed phenomenon. Obtained results are further confirmed in syngeneic mouse model of melanoma in C57BL6 mice. The in vivo results show that SBA-15 do not disturb tumor growth, while both Ph₃Sn(CH₂)₈OH and SBA-15~Cl|Ph₃Sn(CH₂)₈OH significantly decreases tumor volume with an enhancement of the antitumor potential of the tetraorganotin(IV) compound upon immobilization in SBA-15.

Quantitative Study of the Enhanced Content and Chemical Stability of Functional Groups in Mesoporous Silica by In-Situ Co-condensation Synthesis

The chemical stability and content of organic functional groups significantly affect the application of materials in the field of adsorption. In this study, we quantitatively studied the effect of in-situ co-condensation and post grafting on the physico-chemical properties and sorption properties of modified mesoporous silica. The results showed that the grafting method changed the morphology of mesoporous silica while the in-situ method kept the spherical morphology well, and the amino groups were both successfully introduced into the materials. Besides, the amino content of the material prepared by in-situ method (ami-MSN) was 2.71 mmol/g, which was significantly higher than the 0.98 mmol/g of the grafting method (ami-g-MS). Moreover, the chemical stability of functional groups in ami-MSN was much better than ami-g-MS. Furthermore, ami-MSN showed better capability in removing toxic metals of Pb, Cd, Ni, and Cu, and the removal efficiency of Pb reached 98.80%. Besides, ami-MSN exhibited higher dynamic CO2 adsorption of 0.78 mmol/g than ami-g-MS of 0.34 mmol/g. This study revealed the relationship between modification methods and the modification efficiency, functional groups stability, and sorption properties through quantitative comparative studies, which provided a reference for preparing modified mesoporous silica materials with high sorption properties.