Graphene as Photothermal Therapeutic Agents.

Light-assisted hyperthermic therapy is a promising strategy to treat cancer. Graphene and their derivatives with unique physiochemical properties, intrinsic near infrared absorption, and ability to transduce the absorbed light energy into heat, have attracted researchers to use them for photothermal therapy (PTT). In addition, the presence of surface functional groups and large surface area that can facilitate interactions with hydrophobic molecules has favored the use of graphene allotropes for developing PTT-based combinatorial therapies. In this book chapter we have reviewed different graphene-based PTT-assisted photodynamic, gene, chemo, and immunotherapeutic strategies developed to improve the outcome of cancer treatment. We have also discussed how PTT from graphene derivatives can improve the therapeutic outcomes of gene, chemo, and immunotherapies. Finally, this book chapter provides promising insights to develop novel graphene-based multifunctional PTT-assisted combinatorial therapeutics with both imaging and therapeutic regimens to treat cancer.

Graphene: A Promising Theranostic Agent.

Graphene has drawn tremendous interest in the field of nanoscience as a superior theranostic agent owing to its high photostability, aqueous solubility, and low toxicity. This monoatomic thick building block of a carbon allotrope exhibits zero to two-dimensional characteristics with a unique size range within the nanoscale. Their high biocompatibility, quantum yield, and photoluminescent properties make them more demandable in biomedical research. Its application in biomedical sciences has been limited due to its small-scale production. Large-scale production with an easy synthesis process is urgently required to overcome the problem associated with its translational application. Despite all possible drawbacks, the graphene-based drug/gene delivery system is gaining popularity day by day. To date, various studies suggested its application as a theranostic agent for target-specific delivery of chemotherapeutics or antibiotics against various diseases like cancer, Alzheimer's diseases, multidrug resistance diseases, and more. Also, studying the toxicological profile of graphene derivatives is very important before starting its practical use in clinical applications. This chapter has tried to abbreviate several methods and their possible incoming perspective as claimed by researchers for mass production and amplifying graphene-based treatment approaches.

Hyaluronan-Stabilized Redox-Sensitive Nanoassembly for Chemo-Gene Therapy and Dual T1/T2 MR Imaging in Drug-Resistant Breast Cancer Cells.

Tailoring combinatorial therapies along with real-time monitoring strategies has been the major focus of overcoming multidrug resistance in cancer. However, attempting to develop a multifunctional nanoplatform in a single construct leads to compromising therapeutic outcomes. Herein, we developed a simple, theranostic nanoassembly containing a hyaluronic acid-stabilized redox-sensitive (HART) polyethylenimine polyplex composed of a doxorubicin (DOX) intercalated Bcl-2 shRNA encoded plasmid along with a green-synthesized hausmannite (Mn3O4) and hematite (Fe3O4) nanoparticle (GMF). The highly stable HART nanoassembly has enhanced CD44-mediated intracellular uptake along with hyaluronidase (hylase) and redox-responsive drug-gene release. With Bcl-2 gene silencing induced by the successful delivery of HART in multidrug-resistant MCF7 breast cancer cells, the synergistic cytotoxic effect of Bcl-2 silencing and DOX was achieved. In addition, the HART nanoassembly containing GMF exhibited excellent dual MRI contrast (T1/T2) by reducing artifact signals. Overall, the HART nanoassembly with its enhanced theranostic properties has the potential to improve the therapeutic efficacy in future preclinical and clinical trials.

Peroxidase-Mimicking Nanoassembly Mitigates Lipopolysaccharide-Induced Endotoxemia and Cognitive Damage in the Brain by Impeding Inflammatory Signaling in Macrophages.

Oxidative stress during sepsis pathogenesis remains the most-important factor creating imbalance and dysregulation in immune-cell function, usually observed following initial infection. Hydrogen peroxide (H2O2), a potentially toxic reactive oxygen species (ROS), is excessively produced by pro-inflammatory immune cells during the initial phases of sepsis and plays a dominant role in regulating the pathways associated with systemic inflammatory immune activation. In the present study, we constructed a peroxide scavenger mannosylated polymeric albumin manganese dioxide (mSPAM) nanoassembly to catalyze the decomposition of H2O2 responsible for the hyper-activation of pro-inflammatory immune cells. In a detailed manner, we investigated the role of mSPAM nanoassembly in modulating the expression and secretion of pro-inflammatory markers elevated in bacterial lipopolysaccharide (LPS)-mediated endotoxemia during sepsis. Through a facile one-step solution-phase approach, hydrophilic bovine serum albumin reduced manganese dioxide (BM) nanoparticles were synthesized and subsequently self-assembled with cationic mannosylated disulfide cross-linked polyethylenimine (mSP) to formulate mSPAM nanoassembly. In particular, we observed that the highly stable mSPAM nanoassembly suppressed HIF1α expression by scavenging H2O2 in LPS-induced macrophage cells. Initial investigation revealed that a significant reduction of free radicals by the treatment of mSPAM nanoassembly has reduced the infiltration of neutrophils and other leukocytes in a local endotoxemia animal model. Furthermore, therapeutic studies in a systemic endotoxemia model demonstrated that mSPAM treatment reduced TNF-α and IL-6 inflammatory cytokines in serum, in turn circumventing organ damage done by the inflammatory macrophages. Interestingly, we also observed that the reduction of these inflammatory cytokines by mSPAM nanoassembly further prevented IBA-1 immuno-positive microglial cell activation in the brain and consequently improved the cognitive function of the animals. Altogether, the administration of mSPAM nanoassembly scavenged H2O2 and suppressed HIF1α expression in LPS-stimulated macrophages and thereby inhibited the progression of local and systemic inflammation as well as neuroinflammation in an LPS-induced endotoxemia model. This mSPAM nanoassembly system could serve as a potent anti-inflammatory agent, and we further anticipate its successful application in treating various inflammation-related diseases.

Antineuroinflammatory Activities and Neurotoxicological Assessment of Curcumin Loaded Solid Lipid Nanoparticles on LPS-Stimulated BV-2 Microglia Cell Models.

Curcumin, which is a potential antineuroinflammatory and neuroprotective compound, exhibits poor bioavailability in brain cells due to its difficulty in crossing the blood⁻brain barrier and its rapid metabolism during circulation, which decreases its efficacy in treating chronic neuroinflammatory diseases in the central nervous system. The bioavailability and potential of curcumin can be improved by using a nanodelivery system, which includes solid lipid nanoparticles. Curcumin-loaded solid lipid nanoparticles (SLCN) were efficiently developed to have a particle size of about 86 nm and do not exhibit any toxicity in the endothelial brain cells. Furthermore, the curcumin-loaded solid lipid nanoparticles (SLCN) were studied to assess their efficacy in BV-2 microglial cells against LPS-induced neuroinflammation. The SLCN showed a higher inhibition of nitric oxide (NO) production compared to conventional curcumin in a dose-dependent manner. Similarly, the mRNA and proinflammatory cytokine levels were also reduced in a dose-dependent manner when compared to those with free curcumin. Thus, SLCN could be a potential delivery system for curcumin to treat microglia-mediated neuroinflammation.

Recent advancements of hydrogels in immunotherapy: Breast cancer treatment.

Breast cancer is the most prevalent cancer among women and the leading cause of cancer-related deaths in this population. Recent advances in Immunotherapy, or combined immunotherapy, offering a more targeted and less toxic approach, expand the survival rate of patients more than conventional treatment. Notably, hydrogels, a versatile platform provided promising avenues to combat breast cancer in preclinical studies and extended to clinical practices. With advantages such as the alternation of tumor microenvironment, immunomodulation, targeted delivery of therapeutic agents, and their sustained release at specific sites of interest, hydrogels can potentially be used for the treatment of breast cancer. This review highlights the advantages, mechanisms of action, stimuli-responsiveness properties, and recent advancements of hydrogels for treating breast cancer immunotherapy. Moreover, post-treatment and its clinical translations are discussed in this review. The integration of hydrogels in immunotherapy strategies may pave the way for more effective, personalized, and patient-friendly approaches to combat breast cancer, ultimately contributing to a brighter future for breast cancer patients.

Biomineralized Nanoscavenger Abrogates Proinflammatory Macrophage Polarization and Induces Neutrophil Clearance through Reverse Migration during Gouty Arthritis.

The deposition of monosodium urate (MSU) crystals induces the overexpression of reactive oxygen species (ROS) and proinflammatory cytokines in residential macrophages, further promoting the infiltration of inflammatory leukocytes in the joints of gouty arthritis. Herein, a peroxidase-mimicking nanoscavenger was developed by forming manganese dioxide over albumin nanoparticles loaded with an anti-inflammatory drug, indomethacin (BIM), to block the secretion of ROS and COX2-induced proinflammatory cytokines in the MSU-induced gouty arthritis model. In the MSU-induced arthritis mouse model, the BIM nanoparticles alleviated joint swelling, which is attributed to the abrogation of ROS and inflammatory cytokine secretions from proinflammatory macrophages that induces neutrophil infiltration and fluid building up in the inflammation site. Further, the BIM nanoparticle treatment reduced the influx of macrophages and neutrophils in the injured region by blocking migration and inducing reverse migration in the zebrafish larva tail amputation model as well as in MSU-induced peritonitis and air pouch mouse models. Overall, the current strategy of employing biomineralized nanoscavengers for arthritis demonstrates clinical significance in dual blocking of peroxides and COX2 to prevent influx of inflammatory cells into the sites of inflammation.

Thermosusceptible Nitric-Oxide-Releasing Nitrogel for Strengthening Antitumor Immune Responses with Tumor Collagen Diminution and Deep Tissue Delivery during NIR Laser-Assisted Photoimmunotherapy.

Combined cancer immunotherapy has demonstrated promising potential with an amplified antitumor response and immunosuppressive tumor microenvironment (TME) modulation. However, one of the main issues that cause treatment failure is the poor diffusion and insufficient penetration of therapeutic and immunomodulatory agents in solid tumors. Herein, a cancer treatment approach that combines photothermal therapy (PTT) and nitric oxide (NO) gas therapy for tumor extracellular matrix (ECM) degradation, along with NLG919, an indoleamine 2,3-dioxygenase (IDO) inhibitor that reduces tryptophan catabolism to kynurenine, and DMXAA, a stimulator of interferon gene (STING) agonist that stimulates antigen cross-presentation, is proposed to overcome this issue. Upon NIR (808 nm) laser irradiation, NO-GEL achieved the desired thermal ablation by releasing sufficient tumor antigens through immunogenic cell death (ICD). NO delivery triggered local diffusion of excess NO gas for effectively degrading tumor collagen in the ECM, homogeneously delivered NLG919 throughout the tumor tissue, inhibited IDO expression that was upregulated by PTT, and reduced the immune suppressive activities. The sustained release of DMXAA prolonged dendritic cell maturation and CD8+ T cell activation against the tumor. In summary, NO-GEL therapeutics offer a significant tumor regression with PTT and STING agonist combination that stimulates a durable antitumor immune response. Additional unification of IDO inhibition during PTT supplements the immunotherapy by reducing the T cell apoptosis and immune suppressive cell infiltration to TME. NO-GEL with the STING agonist and IDO inhibitor is an effective therapeutic combination to counter possible limitations during solid tumor immunotherapy.

Hyaluronan-coated Prussian blue nanoparticles relieve LPS-induced peritonitis by suppressing oxidative species generation in tissue-resident macrophages.

Excessive inflammatory response during sepsis causes irreversible damage to healthy tissues and results in multi-organ failure. During infection, bacterial endotoxin-triggered inflammatory responses in macrophages facilitate the recruitment of circulating leukocytes, including neutrophils and monocytes. A key component that aggravates the systemic inflammatory response is the generation of stable reactive oxygen species such as hydrogen peroxide (H2O2). In this study, we present a versatile strategy to reduce the activation of tissue-resident macrophages and prevent leukocyte infiltration in an LPS-induced endotoxemia model. We designed and synthesized hyaluronic acid-stabilized Prussian blue (HAPB) nanoparticles and validated their activity in the dismutation of H2O2 in LPS-induced tissue-resident macrophages. Hyaluronic acid provided stability and enhanced the intracellular uptake of insoluble Prussian blue via the CD44 receptor on LPS-activated macrophages. Following HAPB administration to an LPS-induced peritonitis murine model, the level of M1 inflammatory macrophage population decreased, and the infiltration of neutrophils along with monocytes was suppressed. Overall, we have developed biocompatible Prussian blue nanoparticles to ameliorate inflammatory stress in LPS-induced endotoxemia by scavenging the intracellular peroxide thereby inhibiting inflammatory cascade in tissue-resident macrophages. Therefore, HAPB nanoparticles may potentially be used as novel nano-stress relievers in sepsis. The nanomaterials may have clinical application in sepsis and in other inflammatory diseases involving peroxides as key inflammatory agents.

Combination of STING and TLR 7/8 Agonists as Vaccine Adjuvants for Cancer Immunotherapy.

Immunostimulatory adjuvants that potently activate antigen-presenting cells and (in turn) prime cytotoxic T cells are a key component of anticancer vaccines. In this study, we investigated a multi-adjuvant approach combining a TLR 7/8 agonist (522) and a STING agonist (DMXAA) to promote enhanced antigen cross-presentation, stimulate specific antitumor T-cell responses, and provide improved anticancer efficacy. In vitro experiments using bone marrow-derived dendritic cells (BMDCs) confirmed enhanced activation with the 522-DMXAA combination based on both co-stimulatory molecule expression and pro-inflammatory cytokine secretion. The immunization of mice with vaccines comprising both 522 and DMXAA resulted in greater antitumor efficacy in B16F10 melanoma and MB49 bladder tumor models relative to mono-agonist vaccines. Flow cytometry-based analysis of immune cells from immunized mice revealed the significant activation of antigen-presenting cells, increased numbers of activated and Ag-specific CD8+ T cells in the spleen and lymph nodes, modest NK cell activation, and an overall reduction in CD206+ macrophages. These results were supported by an increase in the levels of IFN-γ and a reduction in IL-10 levels in the sera. Taken together, these findings demonstrate the potential of the TLR7/8 and STING agonist combination as vaccine adjuvants to activate both innate and adaptive immune responses.

Heat-Confined Tumor-Docking Reversible Thermogel Potentiates Systemic Antitumor Immune Response During Near-Infrared Photothermal Ablation in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) features immunologically "cold" tumor microenvironments with limited cytotoxic T lymphocyte (CTL) infiltration. Although ablation therapies have demonstrated modulation of "cold" TNBC tumors to inflamed "hot" tumors, recruitment of myeloid derived suppressor cells (MDSCs) at the tumors post ablation therapies prevents the infiltration of CTLs and challenge the antitumor potentials of T-cell therapies. Here, a thermal ablation immunotherapy strategy is developed to prevent the immune suppressive effects of MDSCs during photothermal ablation and induce a durable systemic antitumor immunity to eradicate TNBC tumors. An injectable pluronic F127/hyaluronic acid (HA)-based hydrogel embedded with manganese dioxide (BM) nanoparticles and TLR7 agonist resiquimod (R848) (BAGEL-R848), is synthesized to induce in situ laser-assisted gelation of the hydrogel and achieve desired ablation temperatures at a low laser-exposure time. Upon 808-nm laser irradiation, a significant reduction in the tumor burden is observed in BAGEL-R848-injected 4T1 tumor-bearing mice. The ablation induced immunogenic cell death and sustained release of R848 from BAGEL-R848 promotes dendritic cell maturation and reduced MDSCs localization in tumors. In addition, inflammatory M1 macrophages and CD8+IFN+ CTL are enriched in distant tumors in bilateral 4T1 tumor model, preventing metastatic tumor growth and signifying the potential of BAGEL-R848 to treat TNBC.

In Situ Oxygenic Nanopods Targeting Tumor Adaption to Hypoxia Potentiate Image-Guided Photothermal Therapy.

Tumor adaption to hypoxic stress not only plays a crucial role in tumor malignancy but also can protect cancer cells from therapeutic interventions. Hence, therapeutic strategies attenuating tumor hypoxia in conjunction with conventional therapies may be an ideal approach. Here, we report the application of in situ oxygenic carbon nano-onion (CNO)/manganese oxide nanopods (iOCOMs) as novel theranostic photothermal transducers to neutralize the oncogenic influence of the hypoxic tumor microenvironment (TME). The developed onion-ring-shaped carbon nanoparticles or carbon nano-onions (CNOs) and iOCOM nanopods (CNO embedded in MnO2 nanosheets) were biologically stable and nontoxic and showed photothermal activity under near-infrared laser irradiation (808 nm). In addition, iOCOM assisted in the dismutation of hydrogen peroxide (H2O2), a potentially toxic reactive oxygen species that is secreted excessively by cancer cells in the hypoxic TME, resulting in in situ oxygenation and repolarization of the hypoxic TME to normoxia. The manganese ions released from iOCOM during the catalysis of H2O2 assisted in TME-responsive T1 magnetic resonance imaging (MRI). The in situ oxygenation by iOCOM in the hypoxic TME downregulated the secretion of hypoxia-inducible factor 1-α, which subsequently interfered with the cancer cell proliferation, favored tumor angiogenesis, and most importantly prevented metastatic epithelial-to-mesenchymal transition of tumor cells. Collectively, this work presents a new paradigm for antitumor strategies by targeting the tumor adaption to hypoxia in combination with photothermal therapy.

Electrospinning Nanofibers for Therapeutics Delivery.

The limitations of conventional therapeutic drugs necessitate the importance of developing novel therapeutics to treat diverse diseases. Conventional drugs have poor blood circulation time and are not stable or compatible with the biological system. Nanomaterials, with their exceptional structural properties, have gained significance as promising materials for the development of novel therapeutics. Nanofibers with unique physiochemical and biological properties have gained significant attention in the field of health care and biomedical research. The choice of a wide variety of materials for nanofiber fabrication, along with the release of therapeutic payload in sustained and controlled release patterns, make nanofibers an ideal material for drug delivery research. Electrospinning is the conventional method for fabricating nanofibers with different morphologies and is often used for the mass production of nanofibers. This review highlights the recent advancements in the use of nanofibers for the delivery of therapeutic drugs, nucleic acids and growth factors. A detailed mechanism for fabricating different types of nanofiber produced from electrospinning, and factors influencing nanofiber generation, are discussed. The insights from this review can provide a thorough understanding of the precise selection of materials used for fabricating nanofibers for specific therapeutic applications and also the importance of nanofibers for drug delivery applications.

Green synthesis of bioactive polysaccharide-capped gold nanoparticles for lymph node CT imaging.

The development of biologically targeted contrast agents for X-ray computed tomography (CT) imaging remains a major challenge. Here, we investigated a green chemistry-based synthesis of lymph node-targeted mannan-capped gold nanoparticles (M-GNPs) as a CT contrast agent. In this study, mannan was used as a reducing and stabilizing agent for gold nanoparticles (AuNPs). M-GNPs were readily internalized by antigen-presenting cells (APCs) through mannose receptors-mediated endocytosis. The M-GNPs, which had a spherical morphology, had an average diameter of 9.18±0.71nm and surface plasmon resonance (SPR) absorption spectra with maximal absorption at 522nm. The M-GNPs displayed a concentration-based X-ray attenuation property with a maximum Hounsfield unit (HU) value of 303.2±10.83. The local administration of M-GNPs led to significantly enhanced X-ray contrast for the imaging of popliteal lymph nodes. These findings demonstrated that M-GNPs can be used as biologically targeted contrast agents for CT imaging.

Self-Assembled, Adjuvant/Antigen-Based Nanovaccine Mediates Anti-Tumor Immune Response against Melanoma Tumor.

Malignant melanoma is a highly aggressive type of cancer that requires radical treatment strategies to inhibit the cancer cell progression and metastasis. In recent years, preclinical research and clinical trials on melanoma treatment have been considerably focused on the adjuvant-based immunotherapy for enhancing the immune response of innate immune cells against cancer cells. However, the clinical outcome of these adjuvant-based treatments is inadequate due to an improper delivery system for these immune activators to reach the target site. Hence, we developed a vaccine formulation containing tumor lysate protein (TL) and poly I:C (PIC) complexed with positively charged poly (sorbitol-co-polyethylenimine (PEI) (PSPEI). The resulting ionic PSPEI-polyplexed antigen/adjuvant (PAA) (PSPEI-PAA) nanocomplexes were stable at the physiological condition, are non-toxic, and have enhanced intracellular uptake of antigen and adjuvant in immature dendritic cells leading to dendritic cell maturation. In the murine B16F10 tumor xenograft model, PSPEI-PAA nanocomplexes significantly suppressed tumor growth and did not exhibit any noticeable sign of toxicity. The level of matured dendritic cells (CD80+/CD86+ cells) in the tumor draining lymph node of PSPEI-PAA treated tumor mice were enhanced and therefore CD8+ T cells infiltration in the tumor were enriched. Additionally, the cytotoxic T lymphocytes (CTLs) assay involving co-culturing of splenocytes isolated from the PSPEI-PAA-treated mice with that of B16F10 cells significantly revealed enhanced cancer killing by the TL-reactivated CTLs compared to untreated control mice bearing tumor. Therefore, we strongly believe that PSPEI-PAA nanocomplexes could be an efficient antigen/adjuvant delivery system and enhance the antitumor immune response against melanoma tumor in the future clinical trials.

Oral siRNA Delivery to Treat Colorectal Liver Metastases.

Convenient multiple dosing makes oral administration an ideal route for delivery of therapeutic siRNA. However, hostile GI environments and nonspecific biological trafficking prevent achieving appropriate bioavailability of siRNA. Here, an orally administered AuNP-siRNA-glycol chitosan-taurocholic acid nanoparticle (AR-GT NPs) was developed to selectively deliver Akt2 siRNA and treat colorectal liver metastases (CLM). AR-GT NPs are dual padlocked nonviral vectors in which the initially formed AuNP-siRNA (AR) conjugates are further encompassed by bifunctional glycol chitosan-taurocholic acid (GT) conjugates. Covering the surface of AR with GT protected the Akt2 siRNA from GI degradation, facilitated active transport through enterocytes, and enhanced selective accumulation in CLM. Our studies in CLM animal models resulted in the reduction in Akt2 production, followed by initiation of apoptosis in cancer cells after oral administration of Akt2 siRNA-loaded AR-GT. This therapeutic siRNA delivery system may be a promising approach in treating liver-associated diseases.

Oral delivery of a therapeutic gene encoding glucagon-like peptide 1 to treat high fat diet-induced diabetes.

The number of people suffering from insulin-independent type 2 diabetes mellitus (T2DM) is ever increasing on a yearly basis. Current anti-diabetic medications often result in adverse weight gain and hypoglycemic episodes. Hypoglycemia can be avoided with glucagon-like peptide (GLP)-1 receptor agonists, which are expensive and require daily injections that may result immune activation. This study demonstrates the use of non-viral vector based oral delivery of GLP-1 gene through enterohepatic recycling pathways of bile acids. Oral administration of the plasmid DNA (pDNA) encoding GLP-1 decreased diabetic glucose levels to the normoglycemic range with significant weight reduction in a high-fat diet (HFD) induced diabetic mouse model and a genetically engineered T2DM rat model. This novel oral GLP1 delivery system is an attractive alternative to treat late-stage T2DM conditions that require repeated insulin injection and can potentially minimize the occurrence of hypoglycemic anomalies.

Photosensitizer conjugated iron oxide nanoparticles for simultaneous in vitro magneto-fluorescent imaging guided photodynamic therapy.

In this study, photosensitizer conjugated iron oxide nanoparticles were strategically designed and prepared for simultaneous PDT and dual-mode fluorescence/MR imaging. The MRI contrast agent Fe3O4 was modified by APTES to functionalize the surface and further to link with heparin-pheophorbide-A conjugates.