Facile Approach to Prepare rGO@Fe3O4 Microspheres for the Magnetically Targeted and NIR-responsive Chemo-photothermal Combination Therapy

Peptide-Hitchhiking for the Development of Nanosystems in Glioblastoma

Glioblastoma (GBM) remains the epitome of aggressiveness and lethality in the spectrum of brain tumors, primarily due to the blood-brain barrier (BBB) that hinders effective treatment delivery, tumor heterogeneity, and the presence of treatment-resistant stem cells that contribute to tumor recurrence. Nanoparticles (NPs) have been used to overcome these obstacles by attaching targeting ligands to enhance therapeutic efficacy. Among these ligands, peptides stand out due to their ease of synthesis and high selectivity. This article aims to review single and multiligand strategies critically. In addition, it highlights other strategies that integrate the effects of external stimuli, biomimetic approaches, and chemical approaches as nanocatalytic medicine, revealing their significant potential in treating GBM with peptide-functionalized NPs. Alternative routes of parenteral administration, specifically nose-to-brain delivery and local treatment within the resected tumor cavity, are also discussed. Finally, an overview of the significant obstacles and potential strategies to overcome them are discussed to provide a perspective on this promising field of GBM therapy.

A novel multifunctional magnetically recyclable BiOBr/ZnFe2O4-GO S-scheme ternary heterojunction: Photothermal synergistic catalysis under Vis/NIR light and NIR-driven photothermal detection of tetracycline

The threat of tetracycline (TC) to human health has become a significant issue that cannot be disregarded. Herein, in order to achieve effective degradation and high-sensitivity detection of TC, BiOBr/ZnFe2O4-GO (BOB/ZFO-GO) S-scheme heterojunction nanocomposites (NCs) have been prepared using hydrothermal method. GO with high light absorption capacity accelerated the electron transfer between BiOBr and ZnFe2O4 nanocrystals and extended the light absorption region of BOB/ZFO NCs. The optimal GO addition of BOB/ZFO-GO NCs could degrade TC solution of 10 mg/L in 80 min and have a high reaction rate constant (k) of 0.072 min-1 under visible/NIR light. According to calculations, the non-metal photocatalyst (BOB/ZFO-GO(2)) with the best degradation performance had a photothermal conversion efficiency of up to 23%. Meanwhile, BOB/ZFO-GO NCs could be recycled by magnetic field. The excellent photocatalytic and photothermal performance could be maintained even after several cycles. In addition, a photothermal detection sensor based on a photothermal material/specific recognition element/tetracycline sandwich-type structure was constructed for the trace detection of TC concentration with a detection limit as low as 10-4 ng/mL. This research provides a unique idea for the multi-functionalization of photocatalysts and has a wide range of potential applications for the identification and treatment of organic wastewater.

Synthesis and characterization of magnetic polymeric nanocomposites for pH-sensitive controlled release of methotrexate

As one of the well-known anticancer drugs, methotrexate (MTX) has been limited in clinical application due to its side effects on normal tissues. This study focused on the one-step hydrothermal synthesis and in vitro evaluation of Fe₃O₄/RGO-PEI as MTX carriers for targeted anticancer therapy. In which, the Fe₃O₄ provided magnetic response properties; RGO acted as a stage for Fe₃O₄ loading and improved the dispersion of Fe₃O₄; polyethylenimine (PEI) was used as a surface modifier and a storehouse for MTX. The prepared Fe₃O₄/RGO-PEI nanocomposites exhibited a suitable size, good stability and magnetic responsibility. And the MTX loading content and loading efficiency were calculated to be 26.6% and 90.5%, respectively. What's more, due to the diffusion and dissolution of PEI, the Fe₃O₄/RGO-PEI-MTX exhibited excellent pH-sensitivity, the values of MTX release rate (%) within 48 h at pH 5.8 and 4.0 were 64.3% and 87.4%, respectively. Furthermore, MTT assays in cancer cells (HepG2) and normal cells (HUVEC) demonstrated that Fe₃O₄/RGO-PEI-MTX exhibited high anticancer activity while low toxicity to normal cells, and also the Fe₃O₄/RGO-PEI composites were practically non-toxic. Thus, our results revealed that Fe₃O₄/RGO-PEI-MTX would be a competitive candidate for targeted delivery and controlled release of MTX.

Metformin loaded injectable silk fibroin microsphere for the treatment of spinal cord injury

The repair of spinal cord injury is a great challenge in clinical. Improving the microenvironment of the injured site is the key strategy for accelerating axon regeneration and synaptic formation. Herein, a kind of silk fibroin microspheres functionalized by metformin through dopamine was developed using water-in-oil emulsification-diffusion method and surface modification technique, and the effect on cortical neuron was evaluated. The results showed that the microspheres showed a uniform size distribution with the diameter of around 60 μm and a concave structure. Moreover, the microspheres possessed good injectability and stability. In addition, the metformin could be successfully immobilized in the silk fibroin microspheres. The cell culture results displayed that the growth and morphology of cortical neurons on the microspheres with metformin concentration of 5 mg/mL and 10 mg/mL were obviously better than that on other samples. Notably, the spread area of single cortical cell on silk fibroin microspheres was increased with the ascending metformin concentration. Therefore, the results indicated that the metformin loaded silk fibroin microsphere could obviously improve the growth and spreading behavior of cortical neuron. The study may provide an important experimental basis for the development of drug loaded injectable biomaterials scaffolds for the treatment of spinal cord injury and have great potential for spinal cord regeneration.

The potential of Graphene Oxide and reduced Graphene Oxide in diagnosis and treatment of Cancer

Nanotechnology is a pioneer field of study; for engineering smart nanosystems in targeted diagnosis and treatment in cancer therapy. The potent therapy for different kinds of solid tumors should ideally target individually the cancerous cells and tissue with no impact on healthy cells in the body. Nano-sized graphene oxide (GO) and reduced graphene oxide (rGO) have phenomenal chemical versatility, high surface area ratio, and supernatural physical properties. The synergistic effects caused by the well-defined assembly of GO and rGO surface generate not only essential optical, mechanical, but also electronic behaviors. Developing novel multifunctional hybrid nanoparticles with great potential is highly considered in multimodal cancer treatment. GO, and rGO are engineered as a programmable targeting delivery system and combed with photonic energy they utilize in photothermal therapy. Its remarkable properties indicated its applications as a biosensor, bio-imaging for cancer diagnosis. In this current review, we show a remarkable highlight about GO, rGO, and discuss the notable applications for cancer diagnosis and treatment, and an overview of possible cellular signaling pathways that are affected by GO, rGO in cancer treatment.

A rGO-DNAzyme assisted fluorescence method for sensitive RNase A activity assay and natural compound screening

As a key regulator of human physiology and metabolic processes, ribonuclease (RNase) A can be used as an important biomarker for predicting human disease occurrence. Hence, establishing sensitive methods for tracking RNase A activity in vitro and in living cells is of great importance. Herein, we present a convenient fluorescence method assisted by reduced graphene oxide (rGO) and DNAzyme mediated fluorescence signal release for RNase A assay. The fluorescence change of the new method showed a positive linear relation with RNase A concentration in the range from 0.5 pg μL^-1 to 1 ng μL^-1 with a detection limit of 0.089 pg μL^-1. By using this method to screen the effector of RNase A from natural compounds, the natural compound of B6 was found to stimulate RNase A activity in vitro and in vivo, the result of which was supported by the real-time imaging of RNase A in living cells. In summary, this fluorescence method with high sensitivity and specificity provides an alternative for RNase A activity assay and effector screening.

Magnetic and GRPR-targeted reduced graphene oxide/doxorubicin nanocomposite for dual-targeted chemo-photothermal cancer therapy

Herein, we design a rGO-based magnetic nanocomposite by decorating rGO with citrate-coated magnetic nanoparticles (CMNP). The magnetic rGO (mrGO) was modified by phospholipid-polyethylene glycol to prepare PEGylated mrGO, for conjugating with gastrin-releasing peptide receptor (GRPR)-binding peptide (mrGOG). The anticancer drug doxorubicin (DOX) was bound to mrGO (mrGOG) by π-π stacking for drug delivery triggered by the low pH value in the endosome. The mrGOG showed enhanced photothermal effect under NIR irradiation, endorsing its role for dual targeted DOX delivery. With efficient DOX release in the endosomal environment and heat generation from light absorption in the NIR range, mrGOG/DOX could be used for combination chemo-photothermal therapy after intracellular uptake by cancer cells. We characterized the physico-chemical as well as biological properties of the synthesized nanocomposites. The mrGOG is stable in biological buffer solution, showing high biocompatibility and minimum hemolytic properties. Using U87 glioblastoma cells, we confirmed the magnetic drug targeting effect in vitro for selective cancer cell killing. The peptide ligand-mediated targeted delivery increases the efficiency of intracellular uptake of both nanocomposite and DOX up to ~3 times due to the over-expressed GRPR on U87 surface, leading to higher cytotoxicity. The increased cytotoxicity using mrGOG over mrGO was shown from a decreased IC₅₀ value (0.70 to 0.48 μg/mL) and an increased cell apoptosis rate (19.8% to 47.1%). The IC₅₀ and apoptosis rate changed further to 0.19 μg/mL and 76.8% in combination with NIR laser irradiation, with the photothermal effect supported from upregulation of heat shock protein HSP70 expression. Using U87 tumor xenograft model created in nude mice, we demonstrated that magnetic guidance after intravenous delivery of mrGOG/DOX could significantly reduce tumor size and prolong animal survival over free DOX and non-magnetic guided groups. Augmented with NIR laser treatment for 5 min, the anti-cancer efficacy significantly improves with elevated cell apoptosis and reduced cell proliferation. Together with safety profiles from hematological as well as major organ histological analysis of treated animals, the mrGOG nanocomposite is an effective nanomaterial for combination chemo-photothermal cancer therapy.

PLGA-based biodegradable microspheres in drug delivery: recent advances in research and application

Biodegradable microspheres have been widely used in the field of medicine due to their ability to deliver drug molecules of various properties through multiple pathways and their advantages of low dose and low side effects. Poly (lactic-co-glycolic acid) copolymer (PLGA) is one of the most widely used biodegradable material currently and has good biocompatibility. In application, PLGA with a specific monomer ratio (lactic acid and glycolic acid) can be selected according to the properties of drug molecules and the requirements of the drug release rate. PLGA-based biodegradable microspheres have been studied in the field of drug delivery, including the delivery of various anticancer drugs, protein or peptide drugs, bacterial or viral DNA, etc. This review describes the basic knowledge and current situation of PLGA biodegradable microspheres and discusses the selection of PLGA polymer materials. Then, the preparation methods of PLGA microspheres are introduced, including emulsification, microfluidic technology, electrospray, and spray drying. Finally, this review summarizes the application of PLGA microspheres in drug delivery and the treatment of pulmonary and ocular-related diseases.

3D MXene microspheres with honeycomb architecture for tumor photothermal/photodynamic/chemo combination therapy

The MXene combining high surface area, prominent biocompatibility, and wide near infrared (NIR) absorption has been recognized as one of the most promising materials for tumor therapy. The application of MXene in tumor therapy is negatively affected by the current design methods lack the control of size distribution and the great tendency to agglomerate as well as poor photodynamic therapy. To solve the above problems, we report a facile strategy to process Ti₃C₂ nanosheets into three-dimensional (3D) structure with honeycomb structure and anti-aggregation properties for synergistic therapy of chemotherapy, photothermal and photodynamic therapy. The 3D MXene is synthesized by spray drying, in which the MXene surface is oxidized to TiO₂. The microspheres present prominent NIR light trigger photothermal effect and excellent NIR light photostability, which respond in an on-off manner. Moreover, the microspheres exhibit outstanding drug-loading capability of doxorubicin (DOX) as high as 87.3%, and substantial singlet oxygen generation (¹O₂) was shown under 808 nm laser and UV light irradiation. Our studies indicate that 3D MXene-DOX could effectively achieve Hela cells killing in vitro, which provides a multifunctional drug delivery platform as a prospective candidate for future combined cancer therapy.

Magnetic reduced graphene oxide as a nano-vehicle for loading and delivery of curcumin

Magnetic nanoparticles have been widely used in the field of nanomedicine as drug delivery vehicles for targeted imaging-guided and controlled drug uptake and release actions. In this work, the loading of curcumin on Fe₃O₄/rGO nanocomposites and their interaction mechanism were investigated by multispectral methods including resonance light scattering (RLS), atomic force microscopy (AFM), circular dichroism (CD) and Fourier transform infrared (FT-IR). Results revealed that the drug loading was a complex process which is not governed by a simple adsorption. The interactions of vitro human serum albumin (HSA) with free curcumin and/or curcumin-Fe₃O₄/rGO complex have been studied. Outcomes from the fluorescence quenching showed that the binding constant of curcumin to HSA increased significantly in the presence of Fe₃O₄/rGO, confirming the enhanced effect of Fe₃O₄/rGO besides its low toxicity towards HSA. Findings from this work verified that Fe₃O₄/rGO nanocomposite has a promising potential as a good drug loading carrier that can be used and broad range of therapies.

Utilizing Edible Agar as a Carrier for Dual Functional Doxorubicin-Fe3O4 Nanotherapy Drugs

The purpose of this study was to use agar as a multifunctional encapsulating material to allow drug and ferromagnetism to be jointly delivered in one nanoparticle. We successfully encapsulated both Fe3O4 and doxorubicin (DOX) with agar as the drug carrier to obtain DOX-Fe3O4@agar. The iron oxide nanoparticles encapsulated in the carrier maintained good saturation of magnetization (41.9 emu/g) and had superparamagnetism. The heating capacity test showed that the specific absorption rate (SAR) value was 18.9 ± 0.5 W/g, indicating that the ferromagnetic nanoparticles encapsulated in the gel still maintained good heating capacity. Moreover, the magnetocaloric temperature could reach 43 °C in a short period of five minutes. In addition, DOX-Fe3O4@agar reached a maximum release rate of 85% ± 3% in 56 min under a neutral pH 7.0 to simulate the intestinal environment. We found using fluorescent microscopy that DOX entered HT-29 human colon cancer cells and reduced cell viability by 66%. When hyperthermia was induced with an auxiliary external magnetic field, cancer cells could be further killed, with a viability of only 15.4%. These results show that agar is an efficient multiple-drug carrier, and allows controlled drug release. Thus, this synergic treatment has potential application value for biopharmaceutical carrier materials.

Engineering of gemcitabine coated nano-graphene oxide sheets for efficient near-infrared radiation mediated in vivo lung cancer photothermal therapy

Gemcitabine (GEM) and its derivatives of deoxycytosine is a promising anticancer candidate which is effective for the treatment of various cancers including lung cancer via cascade targetting Erk/Mek/Raf/Ras pathway and blocking the proliferation of the tumor cells. In this present work, we have described reduced graphene oxide (rGO) in the presence of anticancer utilizing ascorbic acid as reducing agents for lung cancer treatment. GEM reduced graphene oxide (termed as GEM-rGO) has resulted in a smooth and transparent morphological surface, which was confirmed by various spectroscopical investigations. The anticancer drug-loaded rGO has displayed remarkable cytotoxic activities against a panel of lung cancer cell lines when compared to the untreated lung cancer cells. Further, we examined the morphological observation of the cancer cell death was monitored through the fluorescence microscopic examinations. In addition, the cell deaths of the lung cancer cells were observed by the flow cytometry analyses. In addition, the non-toxic nature of potent GEM-rGO and GEM-rGO + NIR was confirmed by in vivo systemic toxicity analysis. Besides, the higher safety feature of the GEM-rGO and GEM-rGO + NIR was evidenced by histological analyses of the mice organs. The subcutaneous injection of GEM-rGO and GEM-rGO + NIR into mice bearing A549 xenografts more effectively inhibited the tumor than the free GEM. Based on the outcomes, we can summarise that the GEM reduced graphene oxide (GEM-rGO) can be used as a promising drug candidate for the treatment of lung cancer in the future.

DNAzyme and rGO based fluorescence assay for Fpg activity analysis, drug screening, and bacterial imaging

Due to the significant role of formamidopyrimidine DNA glycosylase (Fpg) in physiological processes and DNA oxidative damage-related diseases, it is essential to establish sensitive methods for monitoring the Fpg activity in vitro and in vivo so as to illustrate its concrete role in these events. In this work, a sensitive, simple and reliable fluorescence assay was developed by taking the advantages of DNAzyme assisted cascade signal amplification and ultra-high fluorescence quenching efficiency of reduced graphene oxide (rGO). This detection system consisted of DNAzyme, rGO and fluorescence probe allows the activity of Fpg to be detected in a linear range from 0 to 80 U/mL with a detection limit of 0.66 U/mL. With the help of this method, 11 natural compounds were screened, and 7 compounds were identified as activators of Fpg. More importantly, the developed assay was used to monitor the activity of Fpg through fluorescence imaging in living Escherichia coli for the first time. The imaging results visually demonstrated the dynamic activation effect of natural compound Ginsenoside Re on the Fpg of Escherichia coli. In summary, these results indicated that this DNAzyme and rGO based fluorescence assay provides a potent strategy for Fpg quantitative assay in vitro and real-time monitoring in living bacteria, which holds great potential for applying on biological study and Fpg-targeted drug screening.

Physical triggering strategies for drug delivery

Physically triggered systems hold promise for improving drug delivery by enhancing the controllability of drug accumulation and release, lowering non-specific toxicity, and facilitating clinical translation. Several external physical stimuli including ultrasound, light, electric fields and magnetic fields have been used to control drug delivery and they share some common features such as spatial targeting, spatiotemporal control, and minimal invasiveness. At the same time, they possess several distinctive features in terms of interactions with biological entities and/or the extent of stimulus response. Here, we review the key advances of such systems with a focus on discussing their physical mechanisms, the design rationales, and translational challenges.