Fabrication of mesoporous silica nanoparticles for releasable delivery of licorice polysaccharide at the acne site in topical application

Glycyrrhizae Radix et rhizome/licorice is a precious herb in traditional Chinese medicine (TCM). TCM's polysaccharides are medicinally active. But herbal polysaccharides pose some limitations for topical applications. Therefore, this study aimed to utilize licorice polysaccharide via mesoporous silica nanoparticles (MSN) for anti-acne efficacy in topical delivery. The polysaccharide (GGP) was extracted with a 10 % NaOH solution. Chemical characterization suggested that GGP possesses an Mw of 267.9 kDa, comprised primarily of Glc (54.1 %) and Ara (19.12 %), and probably 1,4-linked Glc as a backbone. Then, MSN and amino-functionalized MSN were synthesized, GGP entrapped, and coated with polydopamine (PDA) to produce nanoparticle cargo. The resulted product exhibited 76 % entrapment efficiency and an in vitro release of 89 % at pH 5, which is usually an acne-prone skin's pH. Moreover, it significantly increased Sebocytes' cellular uptake. GGP effectively acted as an anti-acne agent and preserved its efficacy in synthesized nanoparticles. In vivo, the results showed that a 20 % gel of MSN-NH2-GGP@PDA could mediate an inflammatory response via inhibiting pro-inflammatory cytokines and regulating anti-inflammatory cytokines. The MSN-NH2-GGP@PDA inhibited TLR2-activated-MAPK and NF-κB pathway triggered by heat-killed P. acnes. In conclusion, fabricated MSN entrapped GGP for biomimetic anti-acne efficacy in topical application.

Ultrasmall Inorganic Mesoporous Nanoparticles: Preparation, Functionalization, and Application

Ultrasmall mesoporous nanoparticles (<50 nm), a unique porous nanomaterial, have been widely studied in many fields in the last decade owing to the abundant advantages, involving rich mesopores, low density, high surface area, numerous reaction sites, large cavity space, ultrasmall size, etc. This paper presents a review of recent advances in the preparation, functionalization, and applications of ultrasmall inorganic mesoporous nanoparticles for the first time. The soft monomicelles-directed method, in contrast to the hard-template and template-free methods, is more flexible in the synthesis of mesoporous nanoparticles. This is because the amphiphilic micelle has tunable functional blocks, controlled molecule masses, configurations and mesostructures. Focus on the soft micelle directing method, monomicelles could be classified into four types, i.e., the Pluronic-type block copolymer monomicelles, laboratory-synthesized amphiphilic block copolymers monomicelles, the single-molecule star-shaped block copolymer monomicelles, and the small-molecule anionic/cationic surfactant monomicelles. This paper also reviews the functionalization of the inner mesopores and the outer surfaces, which includes constructing the yolkshell structures (encapsulated nanoparticles), anchoring the active components packed on the shell and building an asymmetric Janus architecture. Then, several representative applications, involving catalysis, energy storage, and biomedicines are presented. Finally, the prospects and challenges of controlled synthesis and large-scale applications of ultrasmall mesoporous nanoparticles in the future are foreseen.

Advanced Immunomodulatory Biomaterials for Therapeutic Applications

The multifaceted biological defense system modulating complex immune responses against pathogens and foreign materials plays a critical role in tissue homeostasis and disease progression. Recently developed biomaterials that can specifically regulate immune responses, nanoparticles, graphene, and functional hydrogels have contributed to the advancement of tissue engineering as well as disease treatment. The interaction between innate and adaptive immunity, collectively determining immune responses, can be regulated by mechanobiological recognition and adaptation of immune cells to the extracellular microenvironment. Therefore, applying immunomodulation to tissue regeneration and cancer therapy involves manipulating the properties of biomaterials by tailoring their composition in the context of the immune system. This review provides a comprehensive overview of how the physicochemical attributes of biomaterials determine immune responses, focusing on the physical properties that influence innate and adaptive immunity. This review also underscores the critical aspect of biomaterial-based immune engineering for the development of novel therapeutics and emphasizes the importance of understanding the biomaterials-mediated immunological mechanisms and their role in modulating the immune system.

Dendritic Mesoporous Nanoparticles: Structure, Synthesis and Properties

Recently, a new family of "dendritic" mesoporous silica nanoparticles has attracted great interest with widespread applications. Despite a large number of publications (>800), the terminology of "dendritic" is ambiguous. Understanding what possible "dendritic structures" are, their formation mechanisms and the underlying structure-property relationship is fundamentally important. With the advance of characterization techniques such as electron tomography, two types of tree branch-like and flower-like structures can be distinguished, both described as "dendritic" in literature. In this review, we start with the definition of "dendritic", then provide critical analysis of reported dendritic silica nanoparticles according to their structural classification. We also update the understandings of the formation mechanisms of two types of "dendritic" nanoparticles, with a focus on how to control different structural parameters. Various applications of dendritic mesoporous nanoparticles are also reviewed with a focus in biomedical field, providing new insights into the structure-property relationship in this family of nanomaterials.

MnOx Nanospikes as Nanoadjuvants and Immunogenic Cell Death Drugs with Enhanced Antitumor Immunity and Antimetastatic Effect

Despite the widespread applications of manganese oxide nanomaterials (MONs) in biomedicine, the intrinsic immunogenicity of MONs is still unclear. MnO_x nanospikes (NSs) as tumor microenvironment (TME)-responsive nanoadjuvants and immunogenic cell death (ICD) drugs are proposed for cancer nanovaccine-based immunotherapy. MnO_x NSs with large mesoporous structures show ultrahigh loading efficiencies for ovalbumin and tumor cell fragment. The combination of ICD via chemodynamic therapy and ferroptosis inductions, as well as antigen stimulations, presents a better synergistic immunopotentiation action. Furthermore, the obtained nanovaccines achieve TME-responsive magnetic resonance/photoacoustic dual-mode imaging contrasts, while effectively inhibiting primary/distal tumor growth and tumor metastasis.

General microemulsion synthesis of organic–inorganic hybrid hollow mesoporous silica spheres with enlarged pore size

General microemulsion synthesis of organic–inorganic hybrid hollow mesoporous silica spheres with enlarge pore size with different kinds of pore expanders.

A facile approach to preparation of silica double-shell hollow particles, and their application in gel composite electrolytes

Double-shell hollow particles (DSHPs) have attracted significant attention due to their diverse potential applications. DSHPs are usually obtained by multi-step sacrificial template method which is tedious and inefficient. In this work, a facile synthesis of silica DSHPs has been developed via a novel one-step template method, which is using single-hole hollow particles (SHHPs) as the templates. The shapes and internal structures of the DSHPs were determined by SEM and TEM, and the average diameters of inner and outer shells were about 0.6 and 1.6 μm, respectively. According to FTIR analyses, the compositions of silica DSHPs were identified as well. Furthermore, the silica DSHPs was applied to Li-ion batteries as a modifier of gel polymer electrolyte (GPEs), and the results showed that the gel composite electrolytes (GCEs) could display higher capability, higher ionic conductivity and better rate performance at high current density for GCEs-cell. Properties of the silica DSHPs such as larger specific surface area, more porous structures and Lewis acid-base effect were important for high-performance Li-ion batteries.

Glutathione-Responsive Self-Assembled Magnetic Gold Nanowreath for Enhanced Tumor Imaging and Imaging-Guided Photothermal Therapy

Designing nanomaterials with advanced functions and physical properties to improve cancer diagnosis and treatment has been an enormous challenge. In this work, we report the synthesis of magnetic gold nanowreaths (AuNWs) by combining wet-chemical synthesis with layer-by-layer self-assembly. The presence of Au branches, small junctions, and central holes in AuNWs led to improved photothermal effect compared with Au nanoring seeds and thick Au nanoring with smooth surface. The self-assembly of exceedingly small magnetic iron oxide nanoparticles (ES-MIONs) on the surfaces of AuNWs not only effectively quenched the T₁-weighted magnetic resonance imaging (MRI) ability due to the enhanced T₂ decaying effect but also provided the responsiveness to glutathione (GSH). After intravenous injection, the T₁ signal of magnetic AuNWs initially in the "OFF" state can be intelligently switched on in response to the relatively high GSH concentration in tumor, and the formation of larger assemblies of ES-MIONs improved their tumor delivery compared to ES-MIONs themselves. Thus, the magnetic AuNWs showed higher MRI contrast than ES-MIONs or commercial Magnevist in T₁-weighted MR imaging of tumor. Furthermore, the magnetic AuNWs have absorption in near-infrared range, leading to strong photoacoustic signal and effective photoablation of tumor. Therefore, our GSH-responsive self-assembled magnetic AuNWs could enhance T₁-weighted MRI and photoacoustic imaging of tumor and be used for imaging-guided photothermal therapy.

Near-infrared light triggered drug release from mesoporous silica nanoparticles

Stimuli triggered drug delivery systems enable controlled release of drugs at the optimal space and time, thus achieving optimal therapeutic effects. As one of the most important stimuli used in bioapplications, near-infrared (NIR) light possesses unique advantages such as deep tissue penetration with minimum auto-fluorescence & tissue scattering and high biosafety. Mesoporous silica nanoparticles (MSNs) are one of the most studied nanocarriers; apart from having a high surface area and large pore volume for loading of drugs, they can be easily functionalized with inorganic nanomaterials and stimuli responsive polymers or organic switch molecules, creating possibilities for designing complex stimuli triggered drug delivery systems. Considering the high tissue penetration depth of NIR light and the unique mesoporous structure of MSNs, NIR responsive inorganic nanoparticle functionalized MSNs can be further combined with stimuli responsive materials to form smart "nano-devices" for controlled drug delivery toward tumors, and to date much progress has been made. In this article, recent advances in the design of NIR triggered mesoporous silica drug delivery systems are systematically summarized and some outstanding studies are highlighted. We will also discuss the shortcomings, challenges and opportunities in the field.

Glutathione-depletion mesoporous organosilica nanoparticles as a self-adjuvant and Co-delivery platform for enhanced cancer immunotherapy

Silica based nanoparticles have emerged as a promising vaccine delivery system for cancer immunotherapy, but their bio-degradability, adjuvanticity and the resultant antitumor activity remain to be largely improved. In this study, we report biodegradable glutathione-depletion dendritic mesoporous organosilica nanoparticles (GDMON) with a tetrasulfide-incorporated framework as a novel co-delivery platform in cancer immunotherapy. Functionalized GDMON are capable of co-delivering an antigen protein (ovalbumin) and a toll-like receptor 9 (TLR9) agonist into antigen presenting cells (APCs) and inducing endosome escape. Moreover, decreasing the intracellular glutathione (GSH) level through the -S-S-/GSH redox chemistry increases the ROS generation level both in vitro and in vivo, facilitating cytotoxic T lymphocyte (CTL) proliferation and reducing tumour growth in an aggressive B16-OVA melanoma tumour model. Our results have shown the potential of GDMON as a novel self-adjuvant and co-delivery nanocarrier for cancer vaccine.