Smart Nanocarriers as an Emerging Platform for Cancer Therapy: A Review

Cancer is a group of disorders characterized by uncontrolled cell growth that affects around 11 million people each year globally. Nanocarrier-based systems are extensively used in cancer imaging, diagnostics as well as therapeutics; owing to their promising features and potential to augment therapeutic efficacy. The focal point of research remains to develop new-fangled smart nanocarriers that can selectively respond to cancer-specific conditions and deliver medications to target cells efficiently. Nanocarriers deliver loaded therapeutic cargos to the tumour site either in a passive or active mode, with the least drug elimination from the drug delivery systems. This review chiefly focuses on current advances allied to smart nanocarriers such as dendrimers, liposomes, mesoporous silica nanoparticles, quantum dots, micelles, superparamagnetic iron-oxide nanoparticles, gold nanoparticles and carbon nanotubes, to list a few. Exhaustive discussion on crucial topics like drug targeting, surface decorated smart-nanocarriers and stimuli-responsive cancer nanotherapeutics responding to temperature, enzyme, pH and redox stimuli have been covered.

A Study on the Clinicopathological Profile of the Cases of Colorectal Carcinoma

Aim: To assess the clinicopathological details of patients with colorectal cancer in a tertiary care centre in India and compare it other studies reported in the literature. Study Design: This is a retrospective study conducted on all the patients who were admitted in the period of 2017 to 2020. Place and Duration of Study: Department of Pathology, Saveetha Medical College, Thandalam, Chennai. The data was processed and the manuscript was prepared between June 2020 and January 2021. Methodology: Patient details were collected from the histopathology records and the parameters studied were age, gender, tumour site, histological type, differentiation and tumour stage of the colorectal carcinoma. The sampling was done using the complete enumerate sampling method. The patients diagnosed histopathologically as colorectal carcinoma were included in our study. Results: A total of 51 patients had been admitted in the years 2017, 2018, and 2019 in our institute. There was a female predominance among the patients. The mean age of the patients was lesser than the mean age of colorectal cancer cases in other studies which have been reported in the country. The most common tumour site was rectum in both the sexes and the most common histologic type was adenocarcinoma. The most common histological differentiation was moderate differentiation. Conclusion: The increased incidence in younger patients as compared to previous studies may be attributable to the lifestyle and dietary changes.

Active Targeting Gold Nanoparticle for Chemotherapy Drug Delivery: A Review

Objective Active targeting strategy in chemotherapy drug delivery aims to improve the therapeutic outcomes and minimise the side effects of chemotherapeutics. This review discusses utilising ligands attached to gold nanoparticles (AuNPs) along with several specific ligands attached to AuNPs for active targeting in chemotherapy drug delivery. Key finding Antibodies, peptides, vitamins, DNA, polysaccharides, aptamers, and hormones showed active-targeting abilities as ligands attached to AuNPs. Active-targeting AuNPs enhanced cellular uptake and cytotoxicity in a specific cancer cell in vitro while reducing tumor growth in vivo by improving the photothermal, photodynamic and chemotherapy effects. Active-targeting ligands increased the internalization of AuNPs loaded onto the specific tumour site and minimised the accumulation in the normal site. Conclusion AuNPs with active-targeting ligands such as antibodies, peptides, vitamins, DNA polysaccharides, aptamers, and hormones can improve the therapeutic outcomes of chemotherapeutics and can attenuate the toxicity effect in normal cells. For further research and development, researchers should be addressing AuNP characterization, drug–ligand disposition, active-targeting AuNP quantification, and target-AuNPs pertinence concerning the desired therapeutic outcomes.

Stimuli-Responsive Polymeric Nanomaterials for the Delivery of Immunotherapy Moieties: Antigens, Adjuvants and Agonists

Immunotherapy has been investigated for decades, and it has provided promising results in preclinical studies. The most important issue that hinders researchers from advancing to clinical studies is the delivery system for immunotherapy agents, such as antigens, adjuvants and agonists, and the activation of these agents at the tumour site. Polymers are among the most versatile materials for a variety of treatments and diagnostics, and some polymers are reactive to either endogenous or exogenous stimuli. Utilizing this advantage, researchers have been developing novel and effective polymeric nanomaterials that can deliver immunotherapeutic moieties. In this review, we summarized recent works on stimuli-responsive polymeric nanomaterials that deliver antigens, adjuvants and agonists to tumours for immunotherapy purposes.

Using Natural Adjuvants to Stimulate Anti-Tumour Immune Responses

<p><b>The anti-tumour immune response is often not potent enough to prevent or eradicate disease. Dendritic cells (DCs) are professional antigen-presenting cells that are critical for the initiation of immune responses. While DCs frequently infiltrate tumours, lack of activation together with immuno-suppressive factors from the tumour can hamper an effective anti-tumour immune response.</b></p> <p>In this thesis, the ability of microbial stimuli and danger signals to overcome suppression and re-programme DCs and macrophages to an immuno-stimulatory phenotype was investigated. Whole live Mycobacterium smegmatis and BCG were used to provide multiple pathogen-associated molecular patterns. The intracellularly-recognised toll-like-receptor (TLR) ligands CpG and Poly IC, as well as the extracelullarly recognised TLR ligand LPS, and the danger signal monosodium-urate crystals (MSU) were also included.</p> <p>Bone-marrow derived DCs were found to respond to all adjuvants in vitro and DCs in tumour cell suspensions could be activated ex vivo. To assess the ability of adjuvants to enhance anti-tumour responses in vivo, immune-competent mice bearing established subcutaneous B16F1 melanomas were injected peri-tumorally with the different adjuvants. In line with previous reports, CpG treatment was effective in delaying tumour growth and increasing survival. A similar effect was found with Poly IC, but not with LPS, M. smegmatis, BCG or MSU alone. Combination of M. smegmatis + MSU, however, significantly delayed tumour growth and prolonged survival, while combinations of MSU + BCG or LPS were ineffective. Similar results were obtained using the B16.OVA melanoma and E.G7-OVA thymoma subcutaneous tumour models. In addition, Poly IC and MSU + M. smegmatis reduced primary tumour growth as well as lung metastases in the orthotopic 4T1 breast carcinoma model.</p> <p>Both Poly IC and MSU + M. smegmatis elicited an anti-tumour immune response that required CD8 T cells as well as NK cells. These treatments also resulted in increased proliferation of CD8 T cells and NK cells in tumour-draining lymph nodes, augmented infiltration of effector cells into the tumour, as well as enhanced production of in ammatory cytokines by effector cells and DCs in tumours. In addition, MSU + M. smegmatis also stimulated CD4 T cell proliferation, tumour-infiltrationand activation, while at the same time decreasing the frequency of regulatory T cells in tumours.</p> <p>Activation of a successful immune response to tumours was associated with early induction of IL-12 and IFNʸ, as well as moderate levels of pro-inflammatory cytokines at the tumour site and systemically. Furthermore, anti-tumour activity correlated with the induction of inflammatory monocyte-derived DCs in tumour-draining lymph nodes. These DCs were also observed in adjuvant treated tumours and their appearance was preceded by accumulation of inflammatory monocytes at the tumour site.</p> <p>These findings suggest that specific natural adjuvants can successfully modify the tumour environment and enhance the innate and adaptive anti-tumour immune response to delay tumour progression and increase survival.</p>

Using Natural Adjuvants to Stimulate Anti-Tumour Immune Responses

<p><b>The anti-tumour immune response is often not potent enough to prevent or eradicate disease. Dendritic cells (DCs) are professional antigen-presenting cells that are critical for the initiation of immune responses. While DCs frequently infiltrate tumours, lack of activation together with immuno-suppressive factors from the tumour can hamper an effective anti-tumour immune response.</b></p> <p>In this thesis, the ability of microbial stimuli and danger signals to overcome suppression and re-programme DCs and macrophages to an immuno-stimulatory phenotype was investigated. Whole live Mycobacterium smegmatis and BCG were used to provide multiple pathogen-associated molecular patterns. The intracellularly-recognised toll-like-receptor (TLR) ligands CpG and Poly IC, as well as the extracelullarly recognised TLR ligand LPS, and the danger signal monosodium-urate crystals (MSU) were also included.</p> <p>Bone-marrow derived DCs were found to respond to all adjuvants in vitro and DCs in tumour cell suspensions could be activated ex vivo. To assess the ability of adjuvants to enhance anti-tumour responses in vivo, immune-competent mice bearing established subcutaneous B16F1 melanomas were injected peri-tumorally with the different adjuvants. In line with previous reports, CpG treatment was effective in delaying tumour growth and increasing survival. A similar effect was found with Poly IC, but not with LPS, M. smegmatis, BCG or MSU alone. Combination of M. smegmatis + MSU, however, significantly delayed tumour growth and prolonged survival, while combinations of MSU + BCG or LPS were ineffective. Similar results were obtained using the B16.OVA melanoma and E.G7-OVA thymoma subcutaneous tumour models. In addition, Poly IC and MSU + M. smegmatis reduced primary tumour growth as well as lung metastases in the orthotopic 4T1 breast carcinoma model.</p> <p>Both Poly IC and MSU + M. smegmatis elicited an anti-tumour immune response that required CD8 T cells as well as NK cells. These treatments also resulted in increased proliferation of CD8 T cells and NK cells in tumour-draining lymph nodes, augmented infiltration of effector cells into the tumour, as well as enhanced production of in ammatory cytokines by effector cells and DCs in tumours. In addition, MSU + M. smegmatis also stimulated CD4 T cell proliferation, tumour-infiltrationand activation, while at the same time decreasing the frequency of regulatory T cells in tumours.</p> <p>Activation of a successful immune response to tumours was associated with early induction of IL-12 and IFNʸ, as well as moderate levels of pro-inflammatory cytokines at the tumour site and systemically. Furthermore, anti-tumour activity correlated with the induction of inflammatory monocyte-derived DCs in tumour-draining lymph nodes. These DCs were also observed in adjuvant treated tumours and their appearance was preceded by accumulation of inflammatory monocytes at the tumour site.</p> <p>These findings suggest that specific natural adjuvants can successfully modify the tumour environment and enhance the innate and adaptive anti-tumour immune response to delay tumour progression and increase survival.</p>

Nutritional status and primary tumour site in incurable cancer

ObjectivesWe aimed (1) to assess the nutritional status (NS) using different methods, according to the primary tumour site and (2) to evaluate the performance of these methods in patients with incurable cancer from a reference centre in Brazil.MethodsCross-sectional analysis of data from patients admitted to the palliative care unit of a reference cancer centre in Brazil, between July 2016 and March 2020. The primary tumour site was the independent variable and the NS using different methods were the dependent variables. Logistic regressions were performed.ResultsA total of 2,144 patients were included in the study. The most common primary tumour site was the upper gastrointestinal (GI) tract (18.0%), followed by gynaecological (17.6%) and head and neck (HN) (13.5%). Our results showed that patients with tumours of the upper GI tract followed by HN presented significantly higher risk of worse NS. In contrast, breast tumours, bone and connective tissues and melanoma presented inverse association. The gynaecological cancer was variably associated with nutritional impairment, according to the assessment method.ConclusionsPatients with incurable cancer present high prevalence of NS impairment, depending on the tumour site, shown to be elevated in patients with tumour in the upper GI tract.

Collagen XI Alpha 1 (COL11A1) Expression in the Tumor Microenvironment Drives Neuroblastoma Dissemination

Background Neuroblastoma (NB) is among the most common cancers in children. A highly aggressive form of cancer, NB relies on cells in the microenvironment for dissemination particularly cancer associated fibroblast (CAFs). CAFs synthesise the extracellular matrix to create a scaffold for tumor growth thus enabling the carcinogenesis of NB, Collagen, an abundant scaffold protein produced by CAFs, has been implicated in the creation of an optimal tumor microenvironment, however, the expression profile of collagen within NB is not yet known. Methods We characterised collagen expression within the tumor-stroma boundary by microarray and confirmed by qRT-PCR and immunohistochemistry. Results The collagen marker, COL11A1, was also upregulated in NB CD45+ cells and SMA+ CAFs. Furthermore, SMA+ CAFs led to neuroblastoma cell invasion in an in vitro co-culture system which was subsequently attenuated by gene silencing COL11A1. Immunohistochemical staining of clinical tumor samples revealed that high COL11A1 expression in the stroma adjacent to tumour site, significantly associated with advanced cancer stages, age ≥18 months, undifferentiated tumor status, relapse and poor overall survival. Conclusion Collectively, these results suggest that a COL11A1 signature in the NB microenvironment could represent a novel target for therapeutic intervention.

Paraganglioma of the left common iliac artery: case report and review of the literature

Paraganglioma is a neoplasm derived from the neural crest of the neuroendocrine system. Head and neck account for its more frequent localizations. Parasymphatic paraganglioma have been encountered at cauda equina and iliac vessels. A 37–year old female patient with abdominal pain diagnosed as adnexal mass was surgically operated on at the SMS medical college and research group in Jaipur, Rajasthan, India. During surgery, a retroperitoneal mass was found located lateral to the common left iliac artery. It was completely resected. Microscopic study established characteristics of paraganglionoma. Patient outcome was good. Scanning for other tumour site was negative.

An amphiphilic dendrimer as a light-activable immunological adjuvant for in situ cancer vaccination

Immunological adjuvants are essential for successful cancer vaccination. However, traditional adjuvants have some limitations, such as lack of controllability and induction of systemic toxicity, which restrict their broad application. Here, we present a light-activable immunological adjuvant (LIA), which is composed of a hypoxia-responsive amphiphilic dendrimer nanoparticle loaded with chlorin e6. Under irradiation with near-infrared light, the LIA not only induces tumour cell lysis and tumour antigen release, but also promotes the structural transformation of 2-nitroimidazole containing dendrimer to 2-aminoimidazole containing dendrimer which can activate dendritic cells via the Toll-like receptor 7-mediated signaling pathway. The LIA efficiently inhibits both primary and abscopal tumour growth and induces strong antigen-specific immune memory effect to prevent tumour metastasis and recurrence in vivo. Furthermore, LIA localizes the immunological adjuvant effect at the tumour site. We demonstrate this light-activable immunological adjuvant offers a safe and potent platform for in situ cancer vaccination.