Recombinant human keratinocyte growth factor palifermin reduces oral mucositis and improves patient outcomes after stem cell transplant

Nanotechnology enabled radioprotectants to reduce space radiation-induced reactive oxidative species

Interest in space exploration has seen substantial growth following recent launch and operation of modern space technologies. In particular, the possibility of travel beyond low earth orbit is seeing sustained support. However, future deep space travel requires addressing health concerns for crews under continuous, longer-term exposure to adverse environmental conditions. Among these challenges, radiation-induced health issues are a major concern. Their potential to induce chronic illness is further potentiated by the microgravity environment. While investigations into the physiological effects of space radiation are still under investigation, studies on model ionizing radiation conditions, in earth and micro-gravity conditions, can provide needed insight into relevant processes. Substantial formation of high, sustained reactive oxygen species (ROS) evolution during radiation exposure is a clear threat to physiological health of space travelers, producing indirect damage to various cell structures and requiring therapeutic address. Radioprotection toward the skeletal system components is essential to astronaut health, due to the high radio-absorption cross-section of bone mineral and local hematopoiesis. Nanotechnology can potentially function as radioprotectant and radiomitigating agents toward ROS and direct radiation damage. Nanoparticle compositions such as gold, silver, platinum, carbon-based materials, silica, transition metal dichalcogenides, and ceria have all shown potential as viable radioprotectants to mitigate space radiation effects with nanoceria further showing the ability to protect genetic material from oxidative damage in several studies. As research into space radiation-induced health problems develops, this review intends to provide insights into the nanomaterial design to ameliorate pathological effects from ionizing radiation exposure. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Nanotechnology Approaches to Biology > Cells at the Nanoscale Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Radioprotection of deinococcal exopolysaccharide BRD125 by regenerating hematopoietic stem cells

There is a substantial need for the development of biomaterials for protecting hematopoietic stem cells and enhancing hematopoiesis after radiation damage. Bacterial exopolysaccharide (EPS) has been shown to be very attractive to researchers as a radioprotectant owing to its high antioxidant, anti-cancer, and limited adverse effects. In the present study, we isolated EPS from a novel strain, Deinococcus radiodurans BRD125, which produces EPS in high abundance, and investigated its applicability as a radioprotective biomaterial. We found that EPS isolated from EPS-rich D. radiodurans BRD125 (DeinoPol-BRD125) had an excellent free-radical scavenging effect and reduced irradiation-induced apoptosis. In addition, bone-marrow and spleen-cell apoptosis in irradiated mice were significantly reduced by DeinoPol-BRD125 administration. DeinoPol-BRD125 enhanced the expression of hematopoiesis-related cytokines such as GM-CSF, G-GSF, M-CSF, and SCF, thereby enhancing hematopoietic stem cells protection and regeneration. Taken together, our findings are the first to report the immunological mechanism of a novel radioprotectant, DeinoPol-BRD125, which might constitute an ideal radioprotective and radiation mitigating agent as a supplement drug during radiotherapy.

Breakdown of Symbiosis in Radiation-Induced Oral Mucositis

Oral mucositis is an acute side effect of radiation therapy that is especially common with head and neck cancer treatment. In recent years, several studies have revealed the predisposing factors for mucositis, leading to the pre-treatment of patients to deter the development of opportunistic oral fungal infections. Although many clinical protocols already advise the use of probiotics to counteract inflammation and fungal colonization, preclinical studies are needed to better delineate the mechanisms by which a host may acquire benefits via co-evolution with oral microbiota, probiotics, and fungal commensals, such as Candida albicans, especially during acute inflammation. Here, we review the current understanding of radiation therapy-dependent oral mucositis in terms of pathology, prevention, treatment, and related opportunistic infections, with a final focus on the oral microbiome and how it may be important for future therapy.

Rabbit as an Animal Model for Pharmacokinetics Studies of Enteric Capsule Contains Recombinant Human Keratinocyte Growth Factor Loaded Chitosan Nanoparticles

BACKGROUND

Recombinant human keratinocyte growth factor (rHuKGF) has gained considerable attention by researchers as epithelial cells proliferating agent. Moreover, intravenous truncated rHuKGF (palifermin) has been approved by Food and Drug Administration (FDA) to treat and prevent chemotherapy-induced oral mucositis and small intestine ulceration. The labile structure and short circulation time of rHuKGF in-vivo are the main obstacles that reduce the oral bioactivity and dosage of such proteins at the target site.

OBJECTIVE

Formulation of methacrylic acid-methyl methacrylate copolymer-coated capsules filled with chitosan nanoparticles loaded with rHuKGF for oral delivery.

METHODS

We report on chitosan nanoparticles (CNPs) with diameter < 200 nm, prepared by ionic gelation, loaded with rHuKGF and filled in methacrylic acid-methyl methacrylate copolymercoated capsules for oral delivery. The pharmacokinetic parameters were determined based on the serum levels of rHuKGF, following a single intravenous (IV) or oral dosages using a rabbit model. Furthermore, fluorescent microscope imaging was conducted to investigate the cellular uptake of the rhodamine-labelled rHuKGF-loaded nanoparticles. The proliferation effect of the formulation on FHs 74 Int cells was studied as well by MTT assay.

RESULTS

The mucoadhesive and absorption enhancement properties of chitosan and the protective effect of methacrylic acid-methyl methacrylate copolymer against rHuKGF release at the stomach, low pH, were combined to promote and ensure rHuKGF intestinal delivery and increase serum levels of rHuKGF. In addition, in-vitro studies revealed the protein bioactivity since rHuKGFloaded CNPs significantly increased the proliferation of FHs 74 Int cells.

CONCLUSION

The study revealed that oral administration of rHuKGF-loaded CNPs in methacrylic acid-methyl methacrylate copolymer-coated capsules is practically alternative to the IV administration since the absolute bioavailability of the orally administered rHuKGF-loaded CNPs, using the rabbit as animal model, was 69%. Fluorescent microscope imaging revealed that rhodaminelabelled rHuKGF-loaded CNPs were taken up by FHs 74 Int cells, after 6 hours' incubation time, followed by increase in the proliferation rate.

Effect of basic fibroblast growth factor on radiation-induced oral mucositis in male Syrian hamsters

PURPOSE

Oral mucositis is a frequent and dose-limiting side effect of radiotherapy or chemotherapy in cancer patients. We investigated the effect of basic fibroblast growth factor on radiation-induced oral mucositis in male Syrian hamsters.

METHOD

Oral mucositis was induced in male Syrian hamsters by a single dose of 30-Gy irradiation. Eight days after irradiation, treatment with gel containing trafermin (basic fibroblast growth factor) at 1 or 10 μg up to day-21 was initiated. Re-epithelialization was graded using a six-point scoring system for oral mucositis. Samples of hamster cheek pouches were removed for histopathologic analyses and immunohistochemistry.

RESULTS

The oral-mucositis score decreased in a dose-dependent manner upon trafermin treatment. Trafermin (10 μg) improved oral mucositis significantly compared with vehicle. Histopathology revealed that the degree of re-epithelialization was improved by treatment with trafermin (10 μg) compared with treatment with vehicle.

CONCLUSIONS

Administration of trafermin (10 μg) can prevent mucosal damage to hamster cheek pouches induced by irradiation.

Radiation-Induced Oral Mucositis

Radiation-induced oral mucositis (RIOM) is a major dose-limiting toxicity in head and neck cancer patients. It is a normal tissue injury caused by radiation/radiotherapy (RT), which has marked adverse effects on patient quality of life and cancer therapy continuity. It is a challenge for radiation oncologists since it leads to cancer therapy interruption, poor local tumor control, and changes in dose fractionation. RIOM occurs in 100% of altered fractionation radiotherapy head and neck cancer patients. In the United Sates, its economic cost was estimated to reach 17,000.00 USD per patient with head and neck cancers. This review will discuss RIOM definition, epidemiology, impact and side effects, pathogenesis, scoring scales, diagnosis, differential diagnosis, prevention, and treatment.

Adverse drug events in the oral cavity

Adverse reactions to medications are common and may have a variety of clinical presentations in the oral cavity. Targeted therapies and the new biologic agents have revolutionized the treatment of cancers, autoimmune diseases, and inflammatory and rheumatologic diseases but have also been associated with adverse events in the oral cavity. Some examples include osteonecrosis, seen with not only bisphosphonates but also antiangiogenic agents, and the distinctive ulcers caused by mammalian target of rapamycin inhibitors. As newer therapeutic agents are approved, it is likely that more adverse drug events will be encountered. This review describes the most common clinical presentations of oral mucosal reactions to medications, namely, xerostomia, lichenoid reactions, ulcers, bullous disorders, pigmentation, fibrovascular hyperplasia, white lesions, dysesthesia, osteonecrosis, infection, angioedema, and malignancy. Oral health care providers should be familiar with such events, as they will encounter them in their practice.

Local and systemic pathogenesis and consequences of regimen-induced inflammatory responses in patients with head and neck cancer receiving chemoradiation

Treatment-related toxicities are common among patients with head and neck cancer, leading to poor clinical outcomes, reduced quality of life, and increased use of healthcare resources. Over the last decade, much has been learned about the pathogenesis of cancer regimen-related toxicities. Historically, toxicities were separated into those associated with tissue injury and those with behavioural or systemic changes. However, it is now clear that tissue-specific damage such as mucositis, dermatitis, or fibrosis is no longer the sole consequence of direct clonogenic cell death, and a relationship between toxicities that results in their presentation as symptom clusters has been documented and attributed to a common underlying pathobiology. In addition, the finding that patients commonly develop toxicities representing tissue injury outside radiation fields and side effects such as fatigue or cognitive dysfunction suggests the generation of systemic as well as local mediators. As a consequence, it might be appropriate to consider toxicity syndromes, rather than the traditional approach, in which each side effect was considered as an autonomous entity. In this paper, we propose a biologically based explanation which forms the basis for the diverse constellation of toxicities seen in response to current regimens used to treat cancers of the head and neck.

Chemotherapy-induced mucosal barrier dysfunction: an updated review on the role of intestinal tight junctions

PURPOSE OF REVIEW

Gut toxicity, or mucositis, is a major dose-limiting side effect of chemotherapy that until recently received very little attention. Despite significant research, the mechanisms that underpin chemotherapy-induced gut toxicity (CIGT) remain unclear. Recently however, there has been renewed interest in the role tight junctions play in the pathogenesis of CIGT and associated diarrhea. Thus, this review will cover the role of tight junctions in maintaining gastrointestinal homeostasis and touch on recently proposed mechanisms of how tight junctions may contribute to the development of chemotherapy-induced diarrhea.

RECENT FINDINGS

There is a wealth of anecdotal evidence regarding the role of tight junctions in the pathogenesis of gut toxicity. However, few studies have quantified or assessed the molecular changes in tight junctions in response to chemotherapy. This review will highlight the major findings of these studies and discuss the potential mechanisms by which tight junction disruption and mucosal barrier dysfunction may contribute to diarrhea.

SUMMARY

The significant clinical and economic impact associated with CIGT and diarrhea has only recently been appreciated. This has prompted significant research efforts in an attempt to reveal the pathophysiology of this debilitating complication. Renewed interest has been shown regarding the role of tight junctions in not only maintaining gastrointestinal health, but also contributing to mucosal barrier injury and diarrhea development. More detailed research into the effect chemotherapy has on the molecular characteristics of tight junctions will lead to a better understanding of the pathophysiology of CIGT and may uncover the therapeutic potential of tight junctions in treating diarrhea.

An in vivo screen of secreted proteins identifies adiponectin as a regulator of murine cutaneous wound healing

Skin wounds comprise a serious medical issue for which few pharmacological interventions are available. Moreover, the inflammatory, angiogenic, and proliferative facets of a typical response to a wound each have broader relevance in other pathological conditions. Here we describe a genomics-driven approach to identify secreted proteins that modulate wound healing in a mouse ear punch model. We show that adiponectin, when injected into the wound edge, accelerates wound healing. Notably, adiponectin injection causes upregulation of keratin gene transcripts within hours of treatment, and subsequently promotes collagen organization, formation of pilosebaceous units, and proliferation of cells in the basal epithelial cell layer and pilosebaceous units of healing tissue. The globular domain of adiponectin is sufficient to mediate accelerated dorsal skin wound closure, and the effects are lost in mice that are homozygous null for the adiponectin receptor 1 gene. These findings extend recent observations of a protective role of adiponectin in other tissue injury settings, suggest modulation of AdipoR1 for the clinical management of wounds, and demonstrate a new approach to the identification of regulators of a wound healing response.

Biomarkers of regimen-related mucosal injury

Regimen-related mucosal toxicity is extremely common following cytotoxic chemotherapy and radiotherapy. The alimentary mucosa is particularly susceptible to injury and dysfunction, leading to a constellation of adverse side effects. Currently there is no "one fit" biomarker of such injury. A number of biomarkers have been investigated in the context of gastrointestinal diseases, which may prove useful in the oncology arena. Two of significant potential include citrulline and calprotectin, however more work is required to define the most appropriate settings for their use. Identification of a biomarker that is easily obtained, measured, and accurately indicates mucosal damage, would allow for improved patient diagnosis of toxicities and prompt appropriate intervention. In this review, we highlight the effectiveness of currently examined biomarkers and discuss future avenues for research in this exciting area.

Molecular markers of radiation-related normal tissue toxicity

Over the past five decades, those interested in markers of radiation effect have focused primarily on tumor response. More recently, however, the view has broadened to include irradiated normal tissues-markers that predict unusual risk of side-effects, prognosticate during the prodromal and therapeutic phases, diagnose a particular toxicity as radiation-related, and, in the case of bioterror, allow for tissue-specific biodosimetry. Currently, there are few clinically useful radiation-related biomarkers. Notably, levels of some hormones such as thyroid-stimulating hormone (TSH) have been used successfully as markers of dysfunction, indicative of the need for replacement therapy, and for prevention of cancers. The most promising macromolecular markers are cytokines: TGFbeta, IL-1, IL-6, and TNFalpha being lead molecules in this class as both markers and targets for therapy. Genomics and proteomics are still in nascent stages and are actively being studied and developed.