Postmodification with Polycations Enhances Key Properties of Alginate-Based Multicomponent Microcapsules.

Postmodification of alginate-based microspheres with polyelectrolytes (PEs) is commonly used in the cell encapsulation field to control microsphere stability and permeability. However, little is known about how different applied PEs shape the microsphere morphology and properties, particularly in vivo. Here, we addressed this question using model multicomponent alginate-based microcapsules postmodified with PEs of different charge and structure. We found that the postmodification can enhance or impair the mechanical resistance and biocompatibility of microcapsules implanted into a mouse model, with polycations surprisingly providing the best results. Confocal Raman microscopy and confocal laser scanning microscopy (CLSM) analyses revealed stable interpolyelectrolyte complex layers within the parent microcapsule, hindering the access of higher molar weight PEs into the microcapsule core. All microcapsules showed negative surface zeta potential, indicating that the postmodification PEs get hidden within the microcapsule membrane, which agrees with CLSM data. Human whole blood assay revealed complex behavior of microcapsules regarding their inflammatory and coagulation potential. Importantly, most of the postmodification PEs, including polycations, were found to be benign toward the encapsulated model cells.

Surgical incision pain induced an increase in alcohol consumption in mice.

INTRODUCTION: Large population-based studies have suggested a link between increased alcohol use and reduced pain. In addition, these studies suggest that higher levels of pain intensity are associated with an increase in alcohol consumption and rates of hazardous drinking which potentiates the risk of developing alcohol use disorders (AUD). The mechanisms and determinants of the alcohol-pain interaction can be studied in preclinical studies. METHODS: The overall goal of this study is to use animal models to explore the impact of acute postoperative pain on alcohol intake. To achieve this, we characterized the timeline and levels of alcohol intake and preference in mice after laparotomy in the 2-bottle choice paradigm. RESULTS: Our results show that laparotomy surgery increased alcohol intake and preference in male mice but not females in the 2-bottle choice and 3-bottle choice assays. In addition, ketoprofen administration blocked the increase in alcohol consumption in male mice after laparotomy. We also found that changes in alcohol initial sensitivity and acute functional tolerance, using loss of righting reflex (LORR) response, occur after surgery in mice. CONCLUSION: Taken together, these findings suggests that sex, pain and alcohol sensitivity-related factors may modulate the relationship between alcohol consumption and pain.

Screening hydrogels for antifibrotic properties by implanting cellularly barcoded alginates in mice and a non-human primate.

Screening implantable biomaterials for antifibrotic properties is constrained by the need for in vivo testing. Here we show that the throughput of in vivo screening can be increased by cellularly barcoding a chemically modified combinatorial library of hydrogel formulations. The method involves the implantation of a mixture of alginate formulations, each barcoded with human umbilical vein endothelial cells from different donors, and the association of the identity and performance of each formulation by genotyping single nucleotide polymorphisms of the cells via next-generation sequencing. We used the method to screen 20 alginate formulations in a single mouse and 100 alginate formulations in a single non-human primate, and identified three lead hydrogel formulations with antifibrotic properties. Encapsulating human islets with one of the formulations led to long-term glycaemic control in a mouse model of diabetes, and coating medical-grade catheters with the other two formulations prevented fibrotic overgrowth. High-throughput screening of barcoded biomaterials in vivo may help identify formulations that enhance the long-term performance of medical devices and of biomaterial-encapsulated therapeutic cells.

Comparison of Pain-Like behaviors in two surgical incision animal models in C57BL/6J mice.

Background: Management of pain post-surgery is crucial for tissue healing in both veterinary and human medicine. Overuse of some analgesics such as opioids may lead to addictions and worsen pain syndromes (opioid-induced hyperalgesia), while underuse of it may affect the welfare of the patient. Therefore, the importance of using surgery models in laboratory animals is increasing, with the goal of improving our understanding of pain neurobiology and developing safer analgesics. Methods: We compared the widely used plantar incision model with the laparotomy surgery model and measured pain-related behaviors using both spontaneous and evoked responses in female and male C57BL/6J mice. Additionally, we assessed conditioned place preference (CPP) and sucrose preference tests to measure pain-induced motivation for the analgesic ketoprofen and anhedonia-like behavior. Results: Laparotomized mice showed increased abdominal sensitivity while paw-incised mice showed increased paw thermal and mechanical sensitivity up to seven days post-surgery. Laparotomy surgery reduced all spontaneous behaviors in our study however this effect dissipated by 24 h post-laparotomy. On the other hand, paw incision only reduced the percentage of cage hanging in a sex-dependent manner at 6 h post-incision. We also showed that both surgery models increased conditioned place preference for ketoprofen while preference for sucrose was only reduced at 24 h post-laparotomy. Laporatomy, but not paw incision, induced a decrease in body weight at 24 h post-surgery. Neither surgery model affected fluid intake. Conclusion: Our results indicate that post-surgery hypersensitivity and behavioral deficits may differ by the incision site. Furthermore, factors associated with the surgery including length of the incision, duration of the anesthesia, and the layers that received stitches may affect subsequent spontaneous behaviors. These findings may help to improve drug development or the choice of the effective analgesic, depending on the surgery type.

An Etiological Investigation of Paraneoplastic Cerebellar Degeneration in Ovarian Cancer Patients: A Systematic Review.

Paraneoplastic syndromes (PNS) are uncommon, distinct clinical complications of a primary tumor. Paraneoplastic cerebellar degeneration (PCD) is a PNS that is described as an autoimmune response targeting Purkinje cells in the cerebellum. Ovarian cancer (OC) is one of the most prevalent causes of cancer-related deaths in women. Anti-Yo is the most common onconeural antibody produced in the PCD immune response and is most typically found in ovarian and breast cancer patients. While the current literature highlights the predisposing genetic factors, diagnostic workflows, and treatment options, the pathophysiology of PCD, among other considerations, remains largely unestablished. This review aimed to systematically observe procedural solutions to facilitate an early diagnosis and improve the prognosis of patients with OC-associated PCD. To that end, we examined literature published from 01/01/2015-11/10/2022 indexed in PubMed by using the keywords "paraneoplastic, cerebellar degeneration" combined with "ovarian cancer." Inclusion criteria were met if PCD and OC diagnoses were made and if studies provided adequate patient information. After screening and assessing records for eligibility using the inclusion and exclusion criteria, 18 articles involving 102 patients were included. The typical patient observed in this sample was diagnosed with International Federation of Gynecology and Obstetrics (FIGO) Stage III, high-grade serous carcinoma. The diagnostic workup typically included a clinical evaluation for dysarthria (50%), ataxia (60%), and gait abnormalities (50%), along with multiple imaging modalities and serological findings (90%). Genetic screening for human leukocyte antigen (HLA) haplotype susceptibility for PCD and immune tolerance modulators regulation may also be recommended prior to starting treatment. Findings support the use of corticosteroids (35%) and intravenous immunoglobulin (IVIg) (40%) as viable treatment options for managing PCD in conjunction with systemic therapy for the primary malignancy. A diagnosis of PCD should be considered if a patient has had a malignancy in the past five years with the presence of explicit cerebellar symptoms. This clinical diagnosis can be further supplemented by serologic and radiologic findings. Recognizing PCD symptoms and scheduling genetic and proteomic testing may help with early diagnosis and better prognosis.

Clinically translatable cytokine delivery platform for eradication of intraperitoneal tumors.

Proinflammatory cytokines have been approved by the Food and Drug Administration for the treatment of metastatic melanoma and renal carcinoma. However, effective cytokine therapy requires high-dose infusions that can result in antidrug antibodies and/or systemic side effects that limit long-term benefits. To overcome these limitations, we developed a clinically translatable cytokine delivery platform composed of polymer-encapsulated human ARPE-19 (RPE) cells that produce natural cytokines. Tumor-adjacent administration of these capsules demonstrated predictable dose modulation with spatial and temporal control and enabled peritoneal cancer immunotherapy without systemic toxicities. Interleukin-2 (IL2)-producing cytokine factory treatment eradicated peritoneal tumors in ovarian and colorectal mouse models. Furthermore, computational pharmacokinetic modeling predicts clinical translatability to humans. Notably, this platform elicited T cell responses in NHPs, consistent with reported biomarkers of treatment efficacy without toxicity. Combined, our findings demonstrate the safety and efficacy of IL2 cytokine factories in preclinical animal models and provide rationale for future clinical testing in humans.

Characteristics of male triple negative breast cancer: A population-based study.

Male triple negative breast cancer (TNBC), which lacks expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2), is a very rare entity, comprising only a very small percentage of all male breast cancer cases. Management strategies are typically based off research conducted in female TNBC patients; however, there is still much that remains unknown in the male cohort, such as risk factors for developing these malignancies, the optimal treatment approach, and both short-term and long-term outcome data. In this retrospective cohort study, we aimed to address these concerns by assessing both the characteristics of male patients who develop TNBC as well as their outcomes. We harnessed data from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) Program and identified 66 male patients diagnosed with TNBC between 2010 and 2016. Patients were stratified by several variables including age, insurance status, time period of diagnosis, histology, nodal status, tumor grade, tumor stage at diagnosis, and treatment strategy employed for the assessment of overall survival (OS) differences. Our analysis demonstrated that stage remains the most important prognostic factor for OS, with higher stage corresponding to worse OS. A significant OS benefit was also identified in men undergoing a total mastectomy, compared to partial mastectomy or no surgery at all. We also identified that male patients are more likely to present with more advanced disease stages compared to their female counterparts and, therefore, have worse outcomes on average. This may be due to various factors, including the rarity of male TNBC cases and less clear screening guidelines for male breast cancer in general. Trends toward poorer OS with higher tumor grade, higher tumor T stage, advanced age, earlier time period of diagnosis, and ductal histology were also identified, but did not achieve statistical significance. The remaining variables did not appear to influence outcomes in a meaningful manner. In summary, our study suggests, similar to population studies of women with TNBC, that tumor stage is a major prognostic factor of OS in men with TNBC. The data also suggest that the surgical treatment strategy employed is also likely of significance, with improved OS being seen with total mastectomies over partial mastectomies. Other variables such as tumor grade and T stage also likely play a role, but did not achieve statistical significance owing to the small population size. Owing to the rarity of cases, further studies of male TNBC are needed to better understand this rare entity and guide future management strategies.

Structural changes in alginate-based microspheres exposed to in vivo environment as revealed by confocal Raman microscopy.

A next-generation cure for type 1 diabetes relies on immunoprotection of insulin-producing cells, which can be achieved by their encapsulation in microspheres made of non-covalently crosslinked hydrogels. Treatment success is directly related to the microsphere structure that is characterized by the localization of the polymers constituting the hydrogel material. However, due to the lack of a suitable analytical method, it is presently unknown how the microsphere structure changes in vivo, which complicates evaluation of different encapsulation approaches. Here, confocal Raman microscopy (CRM) imaging was tailored to serve as a powerful new tool for tracking structural changes in two major encapsulation designs, alginate-based microbeads and multi-component microcapsules. CRM analyses before implantation and after explantation from a mouse model revealed complete loss of the original heterogeneous structure in the alginate microbeads, making the intentionally high initial heterogeneity a questionable design choice. On the other hand, the structural heterogeneity was conserved in the microcapsules, which indicates that this design will better retain its immunoprotective properties in vivo. In another application, CRM was used for quantitative mapping of the alginate concentration throughout the microbead volume. Such data provide invaluable information about the microenvironment cells would encounter upon their encapsulation in alginate microbeads.

Reduction of measurement noise in a continuous glucose monitor by coating the sensor with a zwitterionic polymer.

Continuous glucose monitors (CGMs), used by patients with diabetes mellitus, can autonomously track fluctuations in blood glucose over time. However, the signal produced by CGMs during the initial recording period following sensor implantation contains substantial noise, requiring frequent recalibration via fingerprick tests. Here, we show that coating the sensor with a zwitterionic polymer, found via a combinatorial-chemistry approach, significantly reduces signal noise and improves CGM performance. We evaluated the polymer-coated sensors in mice as well as in healthy and diabetic non-human primates, and show that the sensors accurately record glucose levels without the need for recalibration. We also show that the polymer-coated sensors significantly abrogated immune responses to the sensor, as indicated by histology, fluorescent whole-body imaging of inflammation-associated protease activity, and gene expression of inflammation markers. The polymer coating may allow CGMs to become standalone measuring devices.

Alginate encapsulation as long-term immune protection of allogeneic pancreatic islet cells transplanted into the omental bursa of macaques.

The transplantation of pancreatic islet cells could restore glycaemic control in patients with type-I diabetes. Microspheres for islet encapsulation have enabled long-term glycaemic control in diabetic rodent models; yet human patients transplanted with equivalent microsphere formulations have experienced only transient islet-graft function, owing to a vigorous foreign-body reaction (FBR), to pericapsular fibrotic overgrowth (PFO) and, in upright bipedal species, to the sedimentation of the microspheres within the peritoneal cavity. Here, we report the results of the testing, in non-human primate (NHP) models, of seven alginate formulations that were efficacious in rodents, including three that led to transient islet-graft function in clinical trials. Although one month post-implantation all formulations elicited significant FBR and PFO, three chemically modified, immune-modulating alginate formulations elicited reduced FBR. In conjunction with a minimally invasive transplantation technique into the bursa omentalis of NHPs, the most promising chemically modified alginate derivative (Z1-Y15) protected viable and glucose-responsive allogeneic islets for 4 months without the need for immunosuppression. Chemically modified alginate formulations may enable the long-term transplantation of islets for the correction of insulin deficiency.

Islet Microencapsulation: Strategies and Clinical Status in Diabetes.

PURPOSE OF REVIEW: Type 1 diabetes mellitus (T1DM) is an autoimmune disease that results from the destruction of insulin-producing pancreatic ß cells in the islets of Langerhans. Islet cell transplantation has become a successful therapy for specific patients with T1DM with hypoglycemic unawareness. The reversal of T1DM by islet transplantation is now performed at many major medical facilities throughout the world. However, many challenges must still be overcome in order to achieve continuous, long-term successful transplant outcomes. Two major obstacles to this therapy are a lack of islet cells for transplantation and the need for life-long immunosuppressive treatment. Microencapsulation is seen as a technology that can overcome both these limitations of islet cell transplantation. This review depicts the present state of microencapsulated islet transplantation. RECENT FINDINGS: Microencapsulation can play a significant role in overcoming the need for immunosuppression and lack of donor islet cells. This review focuses on microencapsulation and the clinical status of the technology in combating T1DM.