Decreased Lung Metastasis in Triple Negative Breast Cancer Following Locally Delivered Supratherapeutic Paclitaxel-Loaded Polyglycerol Carbonate Nanoparticle Therapy.

Breast cancer is among the most prevalent malignancies, accounting for 685,000 deaths worldwide in 2020, largely due to its high metastatic potential. Depending on the stage and tumor characteristics, treatment involves surgery, chemotherapy, targeted biologics, and/or radiation therapy. However, current treatments are insufficient for treating or preventing metastatic disease. Herein, we describe supratherapeutic paclitaxel-loaded nanoparticles (81 wt % paclitaxel) to treat the primary tumor and reduce the risk of subsequent metastatic lesions in the lungs. Primary tumor volume and lung metastasis are reduced by day 30, compared to the paclitaxel clinical standard treatment. The ultrahigh levels of paclitaxel afford an immunotherapeutic effect, increasing natural killer cell activation and decreasing NETosis in the lung, which limits the formation of metastatic lesions.

Minimally invasive, sustained-release relaxin-2 microparticles reverse arthrofibrosis.

Substantial advances in biotherapeutics are distinctly lacking for musculoskeletal diseases. Musculoskeletal diseases are biomechanically complex and localized, highlighting the need for novel therapies capable of addressing these issues. All frontline treatment options for arthrofibrosis, a debilitating musculoskeletal disease, fail to treat the disease etiology-the accumulation of fibrotic tissue within the joint space. For millions of patients each year, the lack of modern and effective treatment options necessitates surgery in an attempt to regain joint range of motion (ROM) and escape prolonged pain. Human relaxin-2 (RLX), an endogenous peptide hormone with antifibrotic and antifibrogenic activity, is a promising biotherapeutic candidate for musculoskeletal fibrosis. However, RLX has previously faltered through multiple clinical programs because of pharmacokinetic barriers. Here, we describe the design and in vitro characterization of a tailored drug delivery system for the sustained release of RLX. Drug-loaded, polymeric microparticles released RLX over a multiweek time frame without altering peptide structure or bioactivity. In vivo, intraarticular administration of microparticles in rats resulted in prolonged, localized concentrations of RLX with reduced systemic drug exposure. Furthermore, a single injection of RLX-loaded microparticles restored joint ROM and architecture in an atraumatic rat model of arthrofibrosis with clinically derived end points. Finally, confirmation of RLX receptor expression, RXFP1, in multiple human tissues relevant to arthrofibrosis suggests the clinical translational potential of RLX when administered in a sustained and targeted manner.

Sustained Supratherapeutic Paclitaxel Delivery Enhances Irreversible Sarcoma Cell Death.

Risk of locoregional recurrence after sarcoma resection is high, increasing both morbidity and mortality. Intraoperative implantation of paclitaxel (PTX)-eluting polymer films locally delivers sustained, supratherapeutic PTX concentrations to the tumor bed that are not clinically feasible with systemic therapy, thereby reducing recurrence and improving survival in a murine model of recurrent sarcoma. However, the biology underlying increased efficacy of PTX-eluting films is unknown and provides the impetus for this work. In vitro PTX efficacy is time and dose dependent with prolonged exposure significantly decreasing PTX IC50 values for human chondrosarcoma (CS-1) cells (153.9 nmol/L at 4 hours vs. 14.2 nmol/L at 30 hours, P = 0.0001). High-dose PTX significantly inhibits proliferation with in vivo PTX films delivering a dose >130 µmol/L directly to the tumor thereby irreversibly arresting cell cycle and inducing apoptosis in CS-1 as well as patient-derived liposarcoma (LP6) and leiomyosarcoma (LMS20). Supratherapeutic PTX upregulates the expression of p21 in G2-M arrested cells, and irreversibly induces apoptosis followed by cell death, within 4 hours of exposure. Microarray analyses corroborate the finding of poor DNA integrity commonly observed as a final step of apoptosis in CS-1 cells and tumor. Unlike low PTX concentrations at the tumor bed during systemic delivery, supratherapeutic concentrations achieved with PTX-eluting films markedly decrease sarcoma lethality in vivo and offer an alternative paradigm to prevent recurrence.

Lung Cancer in Women.

BACKGROUND: Lung cancer is the leading cause of cancer-related death for women in the United States. Clinical characteristics, histology, epidemiology, and treatment responses are unique for women with lung cancer. METHODS: A literature search of Medline publications from 1989 to 2021 was conducted for lung cancer in women. Subsequent narrative review focused on identified differences in risk factors, diagnosis, and treatment of importance to the surgical care of these patients. RESULTS: Studies investigating lung cancer in which sex differences were explored demonstrated differences in risk factors, histology, and treatment response among women, with a significant postsurgical survival advantage over men (41.8 months vs 26.8 months, P = .007) and greater clinical benefit from anti-PD-1 combined with chemotherapy (hazard ratio, 0.44; 95% confidence interval, 0.25-0.76) compared with men (hazard ratio, 0.76; 95% confidence interval, 0.64-0.91). Smoking remains a dominant risk factor, and multiple clinical trials suggest lung cancer screening provides greater benefit for women. However young nonsmoking patients with lung cancer are 2-fold more likely to be female, advocating for broader sex-based screening criteria. Potential roles of genetic mutations, estrogen signaling, and infectious elements in sex-based differences in presentation, histology, prognosis, and treatment response are explored. CONCLUSIONS: Overall much remains unknown regarding how sex influences lung cancer risk, treatment decisions, and outcomes. However evidence of specific differences in presentation, environmental risk, molecular drivers, and mutational burden support the need to better leverage these sex-associated differences to further improve detection, diagnosis, surgical outcomes, and systemic regimens to advance the overall care strategy for women with lung cancer.

Sustainable glycerol terpolycarbonates as temporary bioadhesives.

We describe the synthesis of poly(glycidyl acetate-co-glycidyl butyrate carbonate)s via the terpolymerization of glycidyl acetate (GA), glycidyl butyrate (GB), and CO2 by a cobalt salen complex in high atom economy. These new non-cytotoxic polycarbonates are pressure-sensitive adhesives, and peel testing shows the adhesive strength ranges from Scotch-Tape® to hot-melt glues based on glycidyl butyrate content. The tunable adherence, benign degradation products, and facile application and removal suggest their utility as temporary adhesives, such as those used in biomedical applications or medical devices. One polymer, (GA-co-GB)-87, exhibits the proper adhesive strength to sufficiently adhere a collagen buttress to the jaws of a steel surgical stapler and easily release the buttress after firing to successfully cut, close, and implant the buttress into lung tissue in an ex vivo sheep model.

The Prognosis of Arthrofibroses: Prevalence, Clinical Shortcomings, and Future Prospects.

Fibrosis is the dysregulated biosynthesis of connective tissue that results from persistent infection, high serum cholesterol, surgery, trauma, or prolonged joint immobilization. As a disease that impacts connective tissue, it is prevalent across the body and disrupts normal extracellular and tissue organization. Ultimately, fibrosis impairs the tissue structural, mechanical, or biochemical function. This review describes the clinical landscape of joint fibrosis, that is, arthrofibrosis, including the risk factors and causes, as well as current clinical treatments and their shortcomings. Because treating arthrofibrosis remains an unmet clinical challenge, we present several animal models used for exploration of the physiopathology of arthrofibrosis and summarize their use for testing novel treatments. We then discuss therapeutics for the prevention or treatment of arthrofibrosis that are in preclinical development and in ongoing clinical trials. We conclude with recent findings from molecular biological studies of arthrofibroses that shed insight on future areas of research for improved treatments.

Alpha2-adrenergic receptor agonists prevent emotional hyperthermia.

Emotionally significant stimuli, including potential threats from the external environment, trigger an increase in body temperature, a response known as emotional hyperthermia. Sympathetically-mediated brown adipose tissue (BAT) thermogenesis contributes substantially to this hyperthermic response. The systemic administration of α2-adrenergic agonists is known to inhibit both febrile and shivering responses. In the present study, we investigated whether systemic administration of clonidine, a α2-adrenoceptor agonist, attenuates the emotional hyperthermia evoked in conscious unrestrained rats suddenly confronted with a second (intruder) rat, itself confined to a small cage. Pre-implanted thermistors were used to measure BAT and body temperature in conscious, freely moving, male Sprague-Dawley rats. The rats were pre-treated with intraperitoneally administered vehicle (Ringer solution) or clonidine (1, 10 and 100 µg/kg). Clonidine, in a dose-dependent manner, reduced the intruder-elicited increases in BAT (log-dose linear regression F(1,16) = 9.52, R2 = 0.37, P < 0.01) and body temperature (F(1,16) = 6.48, R2 = 0.29, P < 0.05). We also investigated, in anesthetized rats, whether systemic clonidine administration inhibits BAT sympathetic nerve discharge evoked via activation of neurons in the lateral habenula (LHb) - a nucleus involved in the regulation of emotional hyperthermia. In anesthetized rats, clonidine abolished the BAT sympathetic nerve discharges elicited via bicuculline-mediated disinhibition of the LHb. These results suggest that activation of central α2-adrenergic receptors attenuates the process of emotional hyperthermia by reduction of BAT thermogenesis.

Sustainable polycarbonate adhesives for dry and aqueous conditions with thermoresponsive properties.

Pressure sensitive adhesives are ubiquitous in commodity products such as tapes, bandages, labels, packaging, and insulation. With single use plastics comprising almost half of yearly plastic production, it is essential that the design, synthesis, and decomposition products of future materials, including polymer adhesives, are within the context of a healthy ecosystem along with comparable or superior performance to conventional materials. Here we show a series of sustainable polymeric adhesives, with an eco-design, that perform in both dry and wet environments. The terpolymerization of propylene oxide, glycidyl butyrate, and CO2, catalyzed by a cobalt salen complex bearing a quaternary ammonium salt, yields the poly(propylene-co-glycidyl butyrate carbonate)s (PPGBC)s. This polymeric adhesive system, composed of environmentally benign building blocks, implements carbon dioxide sequestration techniques, poses minimal environmental hazards, exhibits varied peel strengths from scotch tape to hot-melt wood-glue, and adheres to metal, glass, wood, and Teflon® surfaces.

Activating dopamine D2 receptors reduces brown adipose tissue thermogenesis induced by psychological stress and by activation of the lateral habenula.

Emotional hyperthermia is the increase in body temperature that occurs as a response to an animal detecting a salient, survival-relevant stimulus. Brown adipose tissue (BAT) thermogenesis, controlled via its sympathetic innervation, contributes to this temperature increase. Here, we have used an intruder rat experimental model to determine whether quinpirole-mediated activation of dopamine D2 receptors attenuates emotional hyperthermia in conscious rats. In anesthetized rats, we determined whether systemic quinpirole reduces BAT nerve discharge induced by activation of the medullary raphé and the lateral habenula (LHb). We measured BAT and body temperature with chronically implanted thermistors in conscious, freely moving, individually housed, male rats (resident rats). Either vehicle or quinpirole was administered, intraperitoneally, to the resident rat 30 min before introduction of a caged intruder rat. Quinpirole, in a dose-dependent manner, reduced intruder-elicited increases in BAT and body temperature. Pre-treatment with the D2 antagonist spiperone, but not the selective D1 antagonist SCH-23390, prevented this quinpirole-elicited decrease. In anesthetized rats, quinpirole abolished BAT sympathetic nerve discharge elicited by bicuculline-mediated activation of the LHb, but not the medullary raphé. Thus, activation of dopamine D2 receptors reduces the BAT thermogenesis that contributes to emotional hyperthermia. We provide evidence that these dopamine D2 receptors are located in the thermogenic pathway between the LHb and the lower brainstem pre-sympathetic control centre in the medullary raphé.

Intraarticular injection of relaxin-2 alleviates shoulder arthrofibrosis.

Arthrofibrosis is a prevalent condition affecting greater than 5% of the general population and leads to a painful decrease in joint range of motion (ROM) and loss of independence due to pathologic accumulation of periarticular scar tissue. Current treatment options are limited in effectiveness and do not address the underlying cause of the condition: accumulation of fibrotic collagenous tissue. Herein, the naturally occurring peptide hormone relaxin-2 is administered for the treatment of adhesive capsulitis (frozen shoulder) and to restore glenohumeral ROM in shoulder arthrofibrosis. Recombinant human relaxin-2 down-regulates type I collagen and α smooth muscle actin production and increases intracellular cAMP concentration in human fibroblast-like synoviocytes, consistent with a mechanism of extracellular matrix degradation and remodeling. Pharmacokinetic profiling of a bolus administration into the glenohumeral joint space reveals the brief systemic and intraarticular (IA) half-lives of relaxin-2: 0.96 h and 0.62 h, respectively. Furthermore, using an established, immobilization murine model of shoulder arthrofibrosis, multiple IA injections of human relaxin-2 significantly improve ROM, returning it to baseline measurements collected before limb immobilization. This is in contrast to single IA (sIA) or multiple i.v. (mIV) injections of relaxin-2 with which the ROM remains constrained. The histological hallmarks of contracture (e.g., fibrotic adhesions and reduced joint space) are absent in the animals treated with multiple IA injections of relaxin-2 compared with the untreated control and the sIA- and mIV-treated animals. As these findings show, local delivery of relaxin-2 is an innovative treatment of shoulder arthrofibrosis.

Neurons in ventral tegmental area tonically inhibit sympathetic outflow to brown adipose tissue: possible mediation of thermogenic signals from lateral habenula.

The lateral habenula (LHb), a nucleus involved in the response to salient, especially adverse, environmental events, is implicated in brown adipose tissue (BAT) thermogenesis caused by these events. LHb-elicited thermogenesis involves a neural pathway to the lower brain stem sympathetic control center in the medullary raphé. There are no direct connections from the LHb to the medullary raphé. LHb-mediated behavioral responses involve inhibitory control over the dopamine neurons in the ventral tegmental area (VTA), mediated via an excitatory drive from the LHb to GABAergic neurons in the tail of the VTA. We hypothesized that inhibition of the VTA is also involved in LHb-mediated BAT thermogenesis. To test this hypothesis, inhibition of neurons in the VTA with muscimol increased BAT sympathetic nerve discharge by 22.0 ± 9.2 dBµV ( n = 24, P < 0.0001) and BAT temperature by 1.2 ± 0.1°C ( P < 0.001). This response was abolished by inhibition of the medullary raphé neurons with muscimol. BAT thermogenesis initiated with focal injections of bicuculline in the LHb was reversed by subsequent blockade of GABAA receptors in the VTA with bicuculline. These results suggest that, at least in anesthetized rats, neurons in the VTA tonically inhibit BAT thermogenesis via a link, presently unknown, to the medullary raphé. Removal of this VTA-initiated inhibition is an important mechanism whereby LHb neurons activate BAT thermogenesis.

Thermoregulation and the ultradian basic rest-activity cycle.

Daily life involves interactions with the external environment. In rats these apparently spontaneous interactions, often associated with the search for food, alternate with periods of rest in both the dark and light periods of the 24-hour day. Kleitman, in whose laboratory rapid eye movement sleep was discovered, referred to the temporal pattern as "the basic rest-activity cycle." The active periods of the basic rest-activity cycle occur approximately every 1-2 hours in an irregular stochastic pattern that has been described (perhaps unhelpfully) as ultradian rhythmicity. Both the spontaneous interactions and those evoked by salient, potentially threatening environmental events are accompanied by increases in brown adipose tissue (BAT) temperature of approximately 1°C. The heat produced in BAT contributes to associated increases in the temperature of the brain (approximately 0.8°C) and the body (approximately 0.6°C). These temperature changes require extension of the conventional "homeostasis" framework of temperature regulation. They may function to facilitate the cognitive processing that underlies the vital decision making necessary for safe and effective interaction with the external environment.

Breast Cancer Spheroids Reveal a Differential Cancer Stem Cell Response to Chemotherapeutic Treatment.

An abnormal multicellular architecture is a defining characteristic of breast cancer and, yet, most in vitro tumor models fail to recapitulate this architecture or accurately predict in vivo cellular responses to therapeutics. The efficacy of two front-line chemotherapeutic agents (paclitaxel and cisplatin) are described within three distinct in vitro models employing the triple-negative basal breast cancer cell line MDA-MB-231 and the luminal breast cancer cell line MCF7: a) a 3D collagen embedded multicellular spheroid tumor model, which reflects the architecture and cellular heterogeneity of tumors in vivo; b) a 3D collagen model with a single cell-type diffusely embedded; and c) a 2D monolayer. The MDA-MB-231 embedded spheroid tumor model exhibited the most robust response to chemotherapeutic treatment, and possessed the greatest cancer stem cell (CSC) content. CSC-related genes are elevated across all MDA-MB-231 in vitro models following paclitaxel treatment, indicating that paclitaxel enrichment of chemoresistant CSCs is less dependent on microenvironmental tumor structure, while cisplatin showed a more context-dependent response. In the MCF7 cell models a context-dependent response is observed with paclitaxel treatment increasing the CSC related genes in the 2D monolayer and 3D diffuse models while cisplatin treatment afforded an increase in ALDH1A3 expression in all three models.

Clozapine, chlorpromazine and risperidone dose-dependently reduce emotional hyperthermia, a biological marker of salience.

RATIONALE: We recently introduced a new rat model of emotional hyperthermia in which a salient stimulus activates brown adipose tissue (BAT) thermogenesis and tail artery constriction. Antipsychotic drugs, both classical and second generation, act to reduce excessive assignment of salience to objects and events in the external environment. The close association between salient occurrences and increases in body temperature suggests that antipsychotic drugs may also reduce emotional hyperthermia. OBJECTIVES: We determined whether chlorpromazine, clozapine, and risperidone dose dependently reduce emotionally elicited increases in BAT thermogenesis, cutaneous vasoconstriction, and body temperature in rats. METHODS: Rats, chronically instrumented for measurement of BAT and body temperature and tail artery blood flow, singly housed, were confronted with an intruder rat (confined within a small wire-mesh cage) after systemic pre-treatment of the resident rat with vehicle or antipsychotic agent. BAT and body temperatures, tail blood flow, and behavioral activity were continuously measured. RESULTS: Clozapine (30 µg-2 mg/kg), chlorpromazine (0.1-5 mg/kg), and risperidone (6.25 µg-1 mg/kg) robustly and dose-relatedly reduced intruder-elicited BAT thermogenesis and tail artery vasoconstriction, with consequent dose-related reduction in emotional hyperthermia. CONCLUSIONS: Chlorpromazine, a first-generation antipsychotic, as well as clozapine and risperidone, second-generation agents, dose-dependently reduce emotional hyperthermia. Dopamine D2 receptor antagonist properties of chlorpromazine do not contribute to thermoregulatory effects. Interactions with monoamine receptors are important, and these monoamine receptor interactions may also contribute to the therapeutic effects of all three antipsychotics. Thermoregulatory actions of putative antipsychotic agents may constitute a biological marker of their therapeutic properties.

Lateral habenula regulation of emotional hyperthermia: mediation via the medullary raphé.

The lateral habenula (LHb) has an important role in the behavioural response to salient, usually aversive, events. We previously demonstrated that activation of neurons in the LHb increases brown adipose tissue (BAT) thermogenesis and constricts the cutaneous vascular bed, indicating that the LHb contributes to the central control of sympathetic outflow to thermoregulatory effector organs. We have now investigated whether the LHb mediates BAT thermogenesis elicited by emotional stress, and whether the LHb modulates thermoregulatory sympathetic outflow via the rostral medullary raphé, a key integrative lower brainstem sympathetic control centre. In conscious animals, lesioning the LHb attenuated emotional BAT thermogenesis, suggesting that the LHb is part of the central circuitry mediating emotional hyperthermia. In anesthetized animals, inhibition of neurons in the rostral medullary raphé reversed BAT thermogenesis and cutaneous vasoconstriction elicited by activation of neurons in the LHb, indicating that the LHb-induced autonomic responses are mediated through activation of the rostral medullary raphé neurons. The latency to activate BAT sympathetic discharge from electrical stimulation of the LHb was substantially greater than the corresponding latency after stimulation of the medullary raphé, suggesting that the neuronal pathway connecting those two nuclei is quite indirect.

On-Demand Dissolution of a Dendritic Hydrogel-based Dressing for Second-Degree Burn Wounds through Thiol-Thioester Exchange Reaction.

An adhesive yet easily removable burn wound dressing represents a breakthrough in second-degree burn wound care. Current second-degree burn wound dressings absorb wound exudate, reduce bacterial infections, and maintain a moist environment for healing, but are surgically or mechanically debrided from the wound, causing additional trauma to the newly formed tissues. We have developed an on-demand dissolvable dendritic thioester hydrogel burn dressing for second-degree burn care. The hydrogel is composed of a lysine-based dendron and a PEG-based crosslinker, which are synthesized in high yields. The hydrogel burn dressing covers the wound and acts as a barrier to bacterial infection in an in vivo second-degree burn wound model. A unique feature of the hydrogel is its capability to be dissolved on-demand, via a thiol-thioester exchange reaction, allowing for a facile burn dressing removal.

Control of the Cutaneous Circulation by the Central Nervous System.

The central nervous system (CNS), via its control of sympathetic outflow, regulates blood flow to the acral cutaneous beds (containing arteriovenous anastomoses) as part of the homeostatic thermoregulatory process, as part of the febrile response, and as part of cognitive-emotional processes associated with purposeful interactions with the external environment, including those initiated by salient or threatening events (we go pale with fright). Inputs to the CNS for the thermoregulatory process include cutaneous sensory neurons, and neurons in the preoptic area sensitive to the temperature of the blood in the internal carotid artery. Inputs for cognitive-emotional control from the exteroceptive sense organs (touch, vision, sound, smell, etc.) are integrated in forebrain centers including the amygdala. Psychoactive drugs have major effects on the acral cutaneous circulation. Interoceptors, chemoreceptors more than baroreceptors, also influence cutaneous sympathetic outflow. A major advance has been the discovery of a lower brainstem control center in the rostral medullary raphé, regulating outflow to both brown adipose tissue (BAT) and to the acral cutaneous beds. Neurons in the medullary raphé, via their descending axonal projections, increase the discharge of spinal sympathetic preganglionic neurons controlling the cutaneous vasculature, utilizing glutamate, and serotonin as neurotransmitters. Present evidence suggests that both thermoregulatory and cognitive-emotional control of the cutaneous beds from preoptic, hypothalamic, and forebrain centers is channeled via the medullary raphé. Future studies will no doubt further unravel the details of neurotransmitter pathways connecting these rostral control centers with the medullary raphé, and those operative within the raphé itself. © 2016 American Physiological Society. Compr Physiol 6:1161-1197, 2016.

Cladribine and Fludarabine Nucleotides Induce Distinct Hexamers Defining a Common Mode of Reversible RNR Inhibition.

The enzyme ribonucleotide reductase (RNR) is a major target of anticancer drugs. Until recently, suicide inactivation in which synthetic substrate analogs (nucleoside diphosphates) irreversibly inactivate the RNR-α2ß2 heterodimeric complex was the only clinically proven inhibition pathway. For instance, this mechanism is deployed by the multifactorial anticancer agent gemcitabine diphosphate. Recently reversible targeting of RNR-α-alone coupled with ligand-induced RNR-α-persistent hexamerization has emerged to be of clinical significance. To date, clofarabine nucleotides are the only known example of this mechanism. Herein, chemoenzymatic syntheses of the active forms of two other drugs, phosphorylated cladribine (ClA) and fludarabine (FlU), allow us to establish that reversible inhibition is common to numerous drugs in clinical use. Enzyme inhibition and fluorescence anisotropy assays show that the di- and triphosphates of the two nucleosides function as reversible (i.e., nonmechanism-based) inhibitors of RNR and interact with the catalytic (C site) and the allosteric activity (A site) sites of RNR-α, respectively. Gel filtration, protease digestion, and FRET assays demonstrate that inhibition is coupled with formation of conformationally diverse hexamers. Studies in 293T cells capable of selectively inducing either wild-type or oligomerization-defective mutant RNR-α overexpression delineate the central role of RNR-α oligomerization in drug activity, and highlight a potential resistance mechanism to these drugs. These data set the stage for new interventions targeting RNR oligomeric regulation.