Deferoxamine to Minimize Fibrosis During Radiation Therapy

The role of glutathione peroxidase 4 in neuronal ferroptosis and its therapeutic potential in ischemic and hemorrhagic stroke

Ferroptosis is a type of cell death that depends on iron and is driven by lipid peroxidation, playing a crucial role in neuronal death during stroke. A central element in this process is the inactivation of glutathione peroxidase 4 (GPx4), an antioxidant enzyme that helps maintain redox balance by reducing lipid hydroperoxides. This review examines the critical function of GPx4 in controlling neuronal ferroptosis following ischemic and hemorrhagic stroke. We explore the mechanisms through which GPx4 becomes inactivated in various stroke subtypes. In strokes, excess glutamate depletes glutathione (GSH) and products of hemoglobin breakdown overwhelm GPx4. Studies using genetic models with GPx4 deficiency underscore its vital role in maintaining neuronal survival and function. We also consider new therapeutic approaches to enhance GPx4 activity, including novel small molecule activators, adjustments in GSH metabolism, and selenium supplementation. Additionally, we outline the potential benefits of combining these GPx4-focused strategies with other anti-ferroptotic methods like iron chelation and lipoxygenase inhibition for enhanced neuroprotection. Furthermore, we highlight the significance of understanding the timing of GPx4 inactivation during stroke progression to design effective therapeutic interventions.

Deferoxamine topical cream superior to patch in rescuing radiation-induced fibrosis of unwounded and wounded skin

Topical patch delivery of deferoxamine (DFO) has been studied as a treatment for this fibrotic transformation in irradiated tissue. Efficacy of a novel cream formulation of DFO was studied as a RIF therapeutic in unwounded and excisionally wounded irradiated skin. C57BL/6J mice underwent 30 Gy of radiation to the dorsum followed by 4 weeks of recovery. In a first experiment, mice were separated into six conditions: DFO 50 mg cream (D50), DFO 100 mg cream (D100), soluble DFO injections (DI), DFO 1 mg patch (DP), control cream (Vehicle), and irradiated untreated skin (IR). In a second experiment, excisional wounds were created on the irradiated dorsum of mice and then divided into four treatment groups: DFO 100 mg Cream (W-D100), DFO 1 mg patch (W-DP), control cream (W-Vehicle), and irradiated untreated wounds (W-IR). Laser Doppler perfusion scans, biomechanical testing, and histological analysis were performed. In irradiated skin, D100 improved perfusion compared to D50 or DP. Both D100 and DP enhanced dermal characteristics, including thickness, collagen density and 8-isoprostane staining compared to untreated irradiated skin. D100 outperformed DP in CD31 staining, indicating higher vascular density. Extracellular matrix features of D100 and DP resembled normal skin more closely than DI or control. In radiated excisional wounds, D100 facilitated faster wound healing and increased perfusion compared to DP. The 100 mg DFO cream formulation rescued RIF of unwounded irradiated skin and improved excisional wound healing in murine skin relative to patch delivery of DFO.

Deferoxamine Intradermal Delivery Patch for Treatment of a Beta-Thalassemia Wound

MINI-ABSTRACT

In this study, we present the first-in-human use of topical deferoxamine (DFO) in the treatment of a beta-thalassemia wound. We elected to use DFO on a patient that suffered from a chronic nonhealing wound in the setting of beta-thalassemia. Despite approximately 55 weeks of marginal improvement in healing, this patient's wound healed completely after 21 weeks of treatment with DFO. We believe that DFO has the potential to accelerate healing in beta-thalassemia wounds through iron chelation.

Exploratory Analysis of Image-Guided Ionizing Radiation Delivery to Induce Long-Term Iron Accumulation and Ferritin Expression in a Lung Injury Model: Preliminary Results

BACKGROUND

Radiation therapy (RT) is an integral and commonly used therapeutic modality for primary lung cancer. However, radiation-induced lung injury (RILI) limits the irradiation dose used in the lung and is a significant source of morbidity. Disruptions in iron metabolism have been linked to radiation injury, but the underlying mechanisms remain unclear.

PURPOSE

To utilize a targeted radiation delivery approach to induce RILI for the development of a model system to study the role of radiation-induced iron accumulation in RILI.

METHODS

This study utilizes a Small Animal Radiation Research Platform (SARRP) to target the right lung with a 20 Gy dose while minimizing the dose delivered to the left lung and adjacent heart. Long-term pulmonary function was performed using RespiRate-x64image analysis. Normal-appearing lung volumes were calculated using a cone beam CT (CBCT) image thresholding approach in 3D Slicer software. Quantification of iron accumulation was performed spectrophotometrically using a ferrozine-based assay as well as histologically using Prussian blue and via Western blotting for ferritin heavy chain expression.

RESULTS

Mild fibrosis was seen histologically in the irradiated lung using hematoxylin and eosin-stained fixed tissue at 9 months, as well as using a scoring system from CBCT images, the Szapiel scoring system, and the highest fibrotic area metric. In contrast, no changes in breathing rate were observed, and median survival was not achieved up to 36 weeks following irradiation, consistent with mild lung fibrosis when only one lung was targeted. Our study provided preliminary evidence on increased iron content and ferritin heavy chain expression in the irradiated lung, thus warranting further investigation.

CONCLUSIONS

A targeted lung irradiation model may be a useful approach for studying the long-term pathological effects associated with iron accumulation and RILI following ionizing radiation.

A ROS-responsive loaded desferoxamine (DFO) hydrogel system for traumatic brain injury therapy

Traumatic brain injury (TBI) produces excess iron, and increased iron accumulation in the brain leads to lipid peroxidation and reactive oxygen species (ROSs), which can exacerbate secondary damage and lead to disability and death. Therefore, inhibition of iron overload and oxidative stress has a significant role in the treatment of TBI. Functionalized hydrogels with iron overload inhibiting ability and of oxidative stress inhibiting ability will greatly contribute to the repair of TBI. Herein, an injectable, post-traumatic microenvironment-responsive, ROS-responsive hydrogel encapsulated with deferrioxamine mesylate (DFO) was developed. The hydrogel is rapidly formed via dynamic covalent bonding between phenylboronic acid grafted hyaluronic acid (HA-PBA) and polyvinyl alcohol (PVA), and phenylboronate bonds are used to respond to and reduce ROS levels in damaged brain tissue to promote neuronal recovery. The release of DFO from HA-PBA/PVA hydrogels in response to ROS further promotes neuronal regeneration and recovery by relieving iron overload and thus eradicating ROS. In the Feeney model of Sprague Dawley rats, HA-PBA/PVA/DFO hydrogel treatment significantly improved the behavior of TBI rats and reduced the area of brain contusion in rats. In addition, HA-PBA/PVA/DFO hydrogel significantly reduced iron overload to reduce ROS and could effectively promote post-traumatic neuronal recovery. Its effects were also explored, and notably, HA-PBA/PVA/DFO hydrogel can reduce iron overload as well as ROS, thus protecting neurons from death. Thus, this injectable, biocompatible and ROS-responsive drug-loaded hydrogel has great potential for the treatment of TBI. This work suggests a novel method for the treatment of secondary brain injury by inhibiting iron overload and the oxidative stress response after TBI.

Technical Tips to Reduce Implant Rippling in Staged Pre-pectoral Breast Reconstruction

INTRODUCTION

Pre-pectoral implant-based breast reconstruction (IBR) is becoming increasingly popular, permitting optimal implant positioning on the chest wall, prevention of animation deformity, and reduced patient discomfort. There are, however, concerns related to increased rates of breast implant rippling in pre-pectoral (versus submuscular) IBR, which can prompt a patient to seek revisionary surgery. The aim of this study is to identify factors that can be implemented to reduce implant rippling in the setting of pre-pectoral IBR.

METHODS

A literature review was conducted using the PubMed database to determine the rate of rippling in pre-pectoral IBR. Clinical studies in English were included. Further review was then performed to explore technical strategies associated with reduced rates of rippling in pre-pectoral two-stage breast reconstruction.

RESULTS

Implant rippling has been reported with a rate varying from 0 to 53.8% in 25 studies of pre-pectoral IBR (including both direct-to-implant and two-stage IBR). The majority of studies reviewed did not demonstrate a significant association between BMI and rippling, suggesting that other factors, likely technical and device-related, contribute to the manifestation of implant rippling. Hence, we explored whether specific technical modifications could be implemented that would reduce the risk of rippling in patients undergoing pre-pectoral IBR. Specifically, we highlight the need for close attention to expansion protocol and pocket dimension, expander fill medium and implant characteristics, and the rationale behind adjunctive procedures to reduce implant rippling.

CONCLUSION

Surgical modifications may reduce the incidence of rippling in pre-pectoral breast reconstruction.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Topical Iron Chelator Therapy: Current Status and Future Prospects

Systemic iron chelation therapy has long been used for iron overload, providing a role in returning iron levels to proper homeostatic concentrations. Recently, topical iron chelation therapy has emerged as a potential strategy for treating skin damage. This narrative review explores the current status and future prospects of topical iron chelation therapy for treating ultraviolet (UV) and non-UV skin damage, as well as its potential application in wound healing. The review was conducted through a literature search across PubMed, Web of Science, and EMBASE databases, spanning publications from 1990 to 2023. The selection of articles was focused on primary research studies, either experimental or clinical, that explored the implications and formulations of topical iron chelators used alone or in conjunction with another therapeutic agent. The search strategy employed a combination of terms, including "topical iron chelation", "topical deferoxamine", "UV", "wound healing", "skin inflammation", "radiation-induced fibrosis", and "skin cancer". Relevant studies, including methods, intervention strategies, measured outcomes, and findings, are summarized. The review also considered the potential challenges in translating research findings into clinical practice. Results indicate that topical iron chelators, such as deferoxamine, are effective in mitigating UV-induced skin damage, reducing tumorigenesis, and decreasing oxidative damage. In addition, the use of these agents in radiation-induced fibrosis has been shown to significantly increase skin elasticity and reduce dermal fibrosis. Several studies also highlight the use of topical iron chelators in difficult-to-treat chronic wounds, such as diabetic neuropathic ulcers and sickle cell ulcers. In conclusion, topical iron chelation therapy represents a novel and promising approach for skin protection and wound healing. Its potential makes it a promising area of future research.

A ferroptosis-targeting ceria anchored halloysite as orally drug delivery system for radiation colitis therapy

Radiation colitis is the leading cause of diarrhea and hematochezia in pelvic radiotherapy patients. This work advances the pathogenesis of radiation colitis from the perspective of ferroptosis. An oral Pickering emulsion is stabilized with halloysite clay nanotubes to alleviate radiation colitis by inhibiting ferroptosis. Ceria nanozyme grown in situ on nanotubes can scavenge reactive oxygen species, and deferiprone was loaded into the lumen of nanotubes to relieve iron stress. These two strategies effectively inhibit lipid peroxidation and rescue ferroptosis in the intestinal microenvironment. The clay nanotubes play a critical role as either a medicine to alleviate colitis, a nanocarrier that targets the inflamed colon by electrostatic adsorption, or an interfacial stabilizer for emulsions. This ferroptosis-based strategy was effective in vitro and in vivo, providing a prospective candidate for radiotherapy protection via rational regulation of specific oxidative stress.

Chelating the valley of death: Deferoxamine's path from bench to wound clinic

There is undisputable benefit in translating basic science research concretely into clinical practice, and yet, the vast majority of therapies and treatments fail to achieve approval. The rift between basic research and approved treatment continues to grow, and in cases where a drug is granted approval, the average time from initiation of human trials to regulatory marketing authorization spans almost a decade. Albeit with these hurdles, recent research with deferoxamine (DFO) bodes significant promise as a potential treatment for chronic, radiation-induced soft tissue injury. DFO was originally approved by the Food and Drug Administration (FDA) in 1968 for the treatment of iron overload. However, investigators more recently have posited that its angiogenic and antioxidant properties could be beneficial in treating the hypovascular and reactive-oxygen species-rich tissues seen in chronic wounds and radiation-induced fibrosis (RIF). Small animal experiments of various chronic wound and RIF models confirmed that treatment with DFO improved blood flow and collagen ultrastructure. With a well-established safety profile, and now a strong foundation of basic scientific research that supports its potential use in chronic wounds and RIF, we believe that the next steps required for DFO to achieve FDA marketing approval will include large animal studies and, if those prove successful, human clinical trials. Though these milestones remain, the extensive research thus far leaves hope for DFO to bridge the gap between bench and wound clinic in the near future.

New insights in ferroptosis: Potential therapeutic targets for the treatment of ischemic stroke

Stroke is a common disease in clinical practice, which seriously endangers people's physical and mental health. The neurovascular unit (NVU) plays a key role in the occurrence and development of ischemic stroke. Different from other classical types of cell death such as apoptosis, necrosis, autophagy, and pyroptosis, ferroptosis is an iron-dependent lipid peroxidation-driven new form of cell death. Interestingly, the function of NVU and stroke development can be regulated by activating or inhibiting ferroptosis. This review systematically describes the NVU in ischemic stroke, provides a comprehensive overview of the regulatory mechanisms and key regulators of ferroptosis, and uncovers the role of ferroptosis in the NVU and the progression of ischemic stroke. We further discuss the latest progress in the intervention of ferroptosis as a therapeutic target for ischemic stroke and summarize the research progress and regulatory mechanism of ferroptosis inhibitors on stroke. In conclusion, ferroptosis, as a new form of cell death, plays a key role in ischemic stroke and is expected to become a new therapeutic target for this disease.

Noninvasive Systemic Modalities for Prevention of Head and Neck Radiation-Associated Soft Tissue Injury: A Narrative Review

BACKGROUND

 Radiation-associated soft tissue injury is a potentially devastating complication for head and neck cancer patients. The damage can range from minor sequelae such as xerostomia, which requires frequent daily maintenance, to destructive degenerative processes such as osteoradionecrosis, which can contribute to flap failure and delay or reverse oral rehabilitation. Despite the need for effective radioprotectants, the literature remains sparse, primarily focused on interventions beyond the surgeon's control, such as maintenance of good oral hygiene or modulation of radiation dose.

METHODS

 This narrative review aggregates and explores noninvasive, systemic treatment modalities for prevention or amelioration of radiation-associated soft tissue injury.

RESULTS

 We highlighted nine modalities with the most clinical potential, which include amifostine, melatonin, palifermin, hyperbaric oxygen therapy, photobiomodulation, pentoxifylline-tocopherol-clodronate, pravastatin, transforming growth factor-β modulators, and deferoxamine, and reviewed the benefits and limitations of each modality. Unfortunately, none of these modalities are supported by strong evidence for prophylaxis against radiation-associated soft tissue injury.

CONCLUSION

 While we cannot endorse any of these nine modalities for immediate clinical use, they may prove fruitful areas for further investigation.

From Chronic Wounds to Scarring: The Growing Health Care Burden of Under- and Over-Healing Wounds

Significance: Wound healing is the largest medical market without an existing small molecule/drug treatment. Both "under-healing" (chronic wounds) and "over-healing" (scarring) cause a substantial biomedical burden and lifelong consequences for patients. These problems cost tens of billions of dollars per year in the United States alone, a number expected to grow as the population ages and the prevalence of common comorbidities (e.g., diabetes) rises. However, no therapies currently exist to produce the "ideal" healing outcome: efficient wound repair through regeneration of normal tissue. Recent Advances: Ongoing research continues to illuminate possible therapeutic avenues for wound healing. By identifying underlying mechanisms of wound repair-for instance, tissue mechanics' role in fibrosis or cell populations that modulate wound healing and scarring-novel molecular targets may be defined. This Advances in Wound Care Forum issue includes reviews of scientific literature and original research from the Hagey Laboratory for Pediatric Regenerative Medicine at Stanford and its alumni, including developing approaches for encouraging wound healing, minimizing fibrosis, and coaxing regeneration. Critical Issues: Wound healing problems reflect an enormous and rapidly expanding clinical burden. The issues of both under- and over-healing wound outcomes will continue to expand as their underlying causes (e.g., diabetes) grow. Targeted treatments are needed to enable wound repair with functional tissue restoration and decreased scarring. Future Directions: Basic scientists will continue to refine understanding of factors driving undesirable wound outcomes. These discoveries are beginning to be translated and, in the coming years, will hopefully form the foundation for antiscarring drugs and other wound therapeutics.

Smooth versus textured tissue expanders in breast reconstruction - A retrospective review of post-operative surgical site infections

BACKGROUND

Textured tissue expanders (TTEs) were introduced to limit migration and reduce capsular contracture, which were inherent to smooth tissue expanders (STEs). Previous reports suggest that textured devices have increased rates of bacterial contamination and biofilm formation in comparison with smooth devices. Recently, the relative increased association of anaplastic large cell lymphoma (ALCL) with textured versus smooth devices has led to increased adoption of smooth devices. The aim of our study is to evaluate the post-operative surgical site infection (SSI) rates of STEs versus TTEs.

METHODS

A retrospective case series was conducted at a single academic teaching hospital from April 2016 to December 2019. The primary outcome variable was the development of a post-operative SSI.

RESULTS

One hundred seventy-seven breasts underwent reconstruction with TTEs and 109 breasts underwent reconstruction with STE. In total, 54 SSIs were recorded (n = 34 TTE; n = 20 STE), with the majority of infections occurring within the first 30 post-operative days (TTE 65%, STE 70%). There was no statistically significant difference in overall post-operative infection rates between TTE and STE groups when broken down into the following time points: <30 day, 30-60 days, and >90 days (p = 0.924). There was no statistically significant difference between infection type (superficial vs. deep, p = 0.932), infection management (medical, surgical, or both, p = 0.409) or salvage results (p = 0.078) seen in STE versus TTE cohort. On multivariate analysis, seroma history was associated with SSI development (OR 3.18, p = 0.041).

CONCLUSION

There was no significant difference in the rate of post-operative SSI following breast reconstruction with STE relative to TTE.

Nanomedicine Targets Iron Metabolism for Cancer Therapy

Iron is an essential element for cell proliferation and homeostasis by engaging in cell metabolism including DNA synthesis, cell cycle, and redox cycling; however, iron overload could contribute to tumor initiation, proliferation, metastasis, and angiogenesis. Therefore, manipulating iron metabolisms, such as using iron chelators, transferrin receptor 1 (TFR1) Abs, and cytotoxic ligands conjugated to transferrin, has become a considerable strategy for cancer therapy. However, there remain major limitations for potential translation to the clinic based on the regulation of iron metabolism in cancer treatment. Nanotechnology has made great advances for cancer treatment by improving the therapeutic potential and lowering the side‐effects of the proved drugs and those under various stages of development. Early studies that combined nanotechnology with therapeutic means for the regulation of iron metabolism have shown certain promise for developing specific treatment options based on the intervention of cancer iron acquisition, transportation, and utilization. In this review, we summarize the current understanding of iron metabolism involved in cancer and review the recent advances in iron‐regulatory nanotherapeutics for improved cancer therapy. We also envision the future development of nanotherapeutics for improved treatment for certain types of cancers.