Heart failure (HF) is a global burden and, irrespective of age, sex, race, nationality, and geography, affects individuals across the world. Several reports mentioned that, globally, more than 64 million people, which accounts for 1% to 3% of the total global population, are living with HF. In the United States, approximately 6.7 million people older than 20 years have some form of HF, and it is expected to rise to 8.5 million (approximately 3% of the US population) by 2030. HF was linked to 85,037 deaths in 2021, which was 45.8% higher than in 2011. The direct and indirect healthcare costs to treat and manage HF keep increasing both in the United States and around the world. There are several different classes of therapeutic agents available to treat HF. The current recommended therapies include the following drug classes: renin-angiotensin-aldosterone system inhibitors, angiotensin receptor-neprilysin inhibitor, diuretics, β-blockers, and sodium-glucose cotransporter inhibitors. The present article reviews the pathophysiology of HF and focuses on the Food and Drug Administration-approved HF therapeutic agents and insights from corresponding clinical studies.

[This corrects the article DOI: 10.14423/SMJ.0000000000001965.].

We investigated the CXCL12/CXCR4 signaling pathway as a regulator of adipose-derived stem cell (ADSC) self-assembling toroidal constructs using collagen hydrogels. ADSCs formed toroid rings when cultured on hydrogel surfaces but failed to do so when mixed within the matrix. Gene expression profiling revealed significant upregulation of the CXCL12/CXCR4 pathway in toroid-forming conditions, supported by immunofluorescence studies that confirmed CXCL12 presence in toroids but not in mixed-in cultures. Early toroid formation was marked by the emergence of CXCL12 expression, correlating with cell migration. Targeted inhibition experiments identified the PI3K pathway as a critical regulator, delaying cell migration by ∼16 h, while N-Cadherin, Ras/Raf, and ERK1/2 inhibition either reduced or halted migration over extended periods. Through Western blot analysis, altered expression of α-Smooth muscle actin and focal adhesion kinase under PI3K inhibition was highlighted thus emphasizing their roles in toroid formation. Lastly, initial coculture studies with 4T1 breast cancer cells unexpectedly showed CXCL12 localization primarily in 4T1 cells within mixed toroids, suggesting modified chemotactic signaling. Our findings establish CXCL12/CXCR4 as crucial for ADSC toroid formation and reveal the pathway's complex involvement in cellular organization and migration, presenting a robust model for exploring cell–cell and cell–matrix interactions relevant to tissue engineering and cancer research.

α-CGRP (alpha-calcitonin gene-related peptide) is a vasoactive and anti-inflammatory neuropeptide that is cardioprotective in transverse aortic constriction (TAC)-induced pressure overload heart failure (HF) models. Our previous investigations established that a peptoid modification of α-CGRP, termed NMEG-CGRP, prevented left ventricular (LV) dysfunction and remodeling when administered subcutaneously every other day for 28 days, starting two days post-TAC surgery (termed prevention study). Here, we determined whether NMEG-CGRP would be cardioprotective when administered after the development of LV dysfunction secondary to TAC surgery (termed treatment study). Starting 15 days post-sham or TAC surgery, we administered NMEG-CGRP (3.6 mg/kg/mouse) subcutaneously every other day for 28 days in mice assigned to treatment groups. In vivo assessments included weekly electrocardiography to evaluate cardiac function and blood sampling for immunophenotyping. On Day 45, mice were euthanized, and hearts were collected for gross, histological, and biochemical analyses. Compared to sham-operated mice, TAC mice exhibited decreased LV ejection fraction and increased hypertrophy, dilation, fibrosis, apoptosis, and oxidative stress. In contrast, TAC mice treated with NMEG-CGRP demonstrated significant improvements in cardiac function and cellular and biochemical parameters when compared to TAC mice. These findings demonstrate the therapeutic potential of NMEG-CGRP in the treatment of established cardiovascular dysfunction and its progression in pressure overload-induced HF.

BackgroundAlpha-calcitonin gene-related peptide (α-CGRP) is a cardioprotective neuropeptide. However, due to low bioavailability, its use as a therapeutic agent is limited. The aim of the present study was to develop a stable and bioactive α-CGRP analog and to determine its cardioprotective effects in a mouse model of heart failure (HF).MethodsWe chemically synthesized a peptide-peptoid hybrid: human α-CGRP containing two monomers of N-methoxy-ethyl glycine peptoid at the N-terminus (NMEG-CGRP). The toxicity, bioactivity, and stability of NMEG-CGRP were determined by MTT-cell viability assay, mouse blood pressure measurement, and in-vitro digestion with Insulin-degrading enzyme (IDE) followed by LC-MS, respectively. Male C57BL6 mice were underwent transverse aortic constriction (TAC) and were divided into: Sham, Sham+NMEG-CGRP, TAC, and TAC+NMEG-CGRP. Two-day post-TAC, NMEG-CGRP (3.6 mg/kg/mouse) was administered subcutaneously on alternate days, for a total of 28 days. Cardiac function was measured weekly using echocardiography. At the endpoint, mice were euthanized, and hearts were collected for analysis.ResultsOur results demonstrated that NMEG-CGRP was non-toxic to rat H9C2 cells, more stable to IDE digestion, and bioactive. TAC-induced pressure-overload decreased ejection fraction and increased cardiac hypertrophy and dilation, fibrosis, apoptosis, oxidative stress, and macrophage infiltration in the left ventricles. NMEG-CGRP administration significantly attenuated these TAC-induced adverse cardiac effects in the HF mice.ConclusionTogether, our results demonstrated that NMEG-CGRP is a non-toxic, stable, and bioactive CGRP-analog, and protects against pressure-induced HF in mice. Thus, NMEG-CGRP is a promising novel CGRP-analog that may be used in the treatment of HF and potentially other cardiac diseases.

The transforming growth factor beta (TGFβ) and Hippo signaling pathways are evolutionarily conserved pathways that play a critical role in cardiac fibroblasts during embryonic development, tissue repair, and fibrosis. TGFβ signaling and Hippo signaling are also important for cardiac cushion remodeling and septation during embryonic development. Loss of TGFβ2 in mice causes cardiac cushion remodeling defects resulting in congenital heart disease. In this study, we used in vitro molecular and pharmacologic approaches in the cushion mesenchymal cell line (tsA58-AVM) and investigated if the Hippo pathway acts as a mediator of TGFβ2 signaling. Immunofluorescence staining showed that TGFβ2 induced nuclear translocation of activated SMAD3 in the cushion mesenchymal cells. In addition, the results indicate increased nuclear localization of Yes-associated protein 1 (YAP1) following a similar treatment of TGFβ2. In collagen lattice formation assays, the TGFβ2 treatment of cushion cells resulted in an enhanced collagen contraction compared to the untreated cushion cells. Interestingly, verteporfin, a YAP1 inhibitor, significantly blocked the ability of cushion cells to contract collagen gel in the absence or presence of exogenously added TGFβ2. To confirm the molecular mechanisms of the verteporfin-induced inhibition of TGFβ2-dependent extracellular matrix (ECM) reorganization, we performed a gene expression analysis of key mesenchymal genes involved in ECM remodeling in heart development and disease. Our results confirm that verteporfin significantly decreased the expression of α-smooth muscle actin (Acta2), collagen 1a1 (Col1a1), Ccn1 (i.e., Cyr61), and Ccn2 (i.e., Ctgf). Western blot analysis indicated that verteporfin treatment significantly blocked the TGFβ2-induced activation of SMAD2/3 in cushion mesenchymal cells. Collectively, these results indicate that TGFβ2 regulation of cushion mesenchymal cell behavior and ECM remodeling is mediated by YAP1. Thus, the TGFβ2 and Hippo pathway integration represents an important step in understanding the etiology of congenital heart disease.

Alpha-calcitonin gene related peptide (α-CGRP) is a potent vasodilator and protects against heart failure and hypertension in various animal models; however, rapid clearance of the peptide from the circulation makes it difficult to use as a therapeutic agent. Recently, we have synthesized two α-CGRP agonist analogs linked with two n-methoxyethylglycine (NMEG) peptoid molecules at either end: 1)- α-CGRP with NMEG molecules at the N-terminal end (N-ter NMEG), and 2)- α-CGRP with NMEG molecules at the C-terminal end (C-ter NMEG). Bioactivity and toxicity of modified peptides were evaluated in in vitro and in vivo conditions. Peptide-peptoid hybrids, N-ter NMEG and C-ter NMEG, were synthesized using a solid-phase peptide synthesis method with a >98% purity. To test the in vitro cell viability of the analogs, rat H9C2 cardiac myocyte cells were treated with 1 μM, 3 μM, and 10 μM concentrations of N-ter NMEG and C-ter NMEG peptides for 4 days followed by an MTT assay. Our in vitro results demonstrated that neither α-CGRP analogs were toxic to H9C2 cells. To test the bioactivity of these peptides, blood pressure (BP) was measured in wild-type C57BL6 mice using a tail-cuff BP analysis system. A bolus dose of 1.2, 3.6, and 12 (in mg/kg b.wt./mouse) of either peptide was injected subcutaneously (n= 4 mice/dose) followed by BP measurement at increasing time points. Our results demonstrate that there is a variance in the bioactivity of the two peptides. Subcutaneous delivery of N-ter NMEG reduced BP similar to the native peptide. After ten minutes of N-ter NMEG delivery, the BP (in mmHg ±SD) at a dose of 1.2 mg/kg was 76 ±5 (baseline BP= 118 ±15), at a dose of 3.6 mg/kg was 79 ±7 (baseline BP= 113 ±9), and at a dose of 12 mg/mg was 83 ±12 (baseline BP= 104 ±6). In contrast, C-ter NMEG administration did not reduce BP at any peptide concentration tested. In summary, in this study we determined that the α-CGRP analog N-ter NMEG, but not C-ter NMEG, is bioactive. Furthermore, N-ter NMEG showed no toxic effects on H9C2 cardiac myocytes in an in vitro viability assay. These results demonstrate that the analog N-ter NMEG is an effective α-CGRP agonist and a promising candidate molecule to treat cardiac diseases.

Alpha-calcitonin gene-related peptide (α-CGRP) and adrenomedullin (AM) are vasoactive peptides that belong to the calcitonin/CGRP peptide superfamily. Numerous studies have established a protective role of α-CGRP and AM in normal cardiovascular function and the pathophysiology of several cardiovascular diseases. Administration of AM or α-CGRP reduces blood pressure in both the hypertensive and normotensive state. Exogenous delivery of AM or α-CGRP significantly protects the heart secondary to hypertension and heart failure. The short half-life of the peptides in the serum, however, has hindered its ability to be an effective treatment option. Additionally, α-CGRP has been shown to play a significant role in precipitating migraine headaches. Hence, α-CGRP antagonists reduce migraine pain and the number of episodes. Currently, four α-CGRP antagonists are approved for the treatment of migraine. Thus, AM/α-CGRP-agonist(s) and α-CGRP-antagonist(s) are clinically relevant agents in the treatment of cardiovascular diseases and migraine, respectively.

Alpha-calcitonin gene-related peptide (α-CGRP) is a vasodilator neuropeptide of the calcitonin gene family. Pharmacological and gene knock-out studies have established a significant role of α-CGRP in normal and pathophysiological states, particularly in cardiovascular disease and migraines. α-CGRP knock-out mice with transverse aortic constriction (TAC)-induced pressure-overload heart failure have higher mortality rates and exhibit higher levels of cardiac fibrosis, inflammation, oxidative stress, and cell death compared to the wild-type TAC-mice. However, administration of α-CGRP, either in its native- or modified-form, improves cardiac function at the pathophysiological level, and significantly protects the heart from the adverse effects of heart failure and hypertension. Similar cardioprotective effects of the peptide were demonstrated in pressure-overload heart failure mice when α-CGRP was delivered using an alginate microcapsules-based drug delivery system. In contrast to cardiovascular disease, an elevated level of α-CGRP causes migraine-related headaches, thus the use of α-CGRP antagonists that block the interaction of the peptide to its receptor are beneficial in reducing chronic and episodic migraine headaches. Currently, several α-CGRP antagonists are being used as migraine treatments or in clinical trials for migraine pain management. Overall, agonists and antagonists of α-CGRP are clinically relevant to treat and prevent cardiovascular disease and migraine pain, respectively. This review focuses on the pharmacological and therapeutic significance of α-CGRP-agonists and -antagonists in various diseases, particularly in cardiac diseases and migraine pain.

Each year, the Microscopy Society of America (MSA) provides several major awards for outstanding contributions to the fields of microscopy and microanalysis and service to the Society. While recipients of these awards are listed under the tab Awards & Scholarships – Society Awards | Microscopy Society of America on the MSA homepage, little information as to why awards were bestowed is provided. This article highlights the contributions of the winners of the 2022 MSA major Society awards and the MSA Fellows. The information presented here represents a short summary of information provided in the awardees’ nomination packages. Guidelines, including deadlines for nominating individuals for these and other MSA awards, can be found at https://www.microscopy .org/awards/society.cfm.

Developing tissues have intricate, three-dimensional (3D) organizations of cells and extracellular matrix (ECM) that provide the framework necessary to meet morphogenic and necessary demands. Migrating cells, in vivo, are exposed to numerous conflicting signals: chemokines, ECM, growth factors, and physical forces. While most of these have been studied individually in vivo or in vitro, our understanding of how cells integrate these various signals is lacking. We previously developed a novel self-organizing cellularized collagen hydrogel model that is adaptable, tunable, reproducible, and capable of mimicking the multitude of stimuli that cells experience. Our model produced self-assembled toroids of cells that were formed by 24 h. Data we present here show toroids initially form as early as 3 h after seeding. Additionally, toroids formed when cells were seeded on various collagen subtypes and were sensitive to the composition of the hydrogel. Moreover, we found differences in remodeling in toroid gels compared to gels with cells embedded in them using both a collagen binding peptide and rheology. Using scanning electron microscopy, we observed toroids forming a crater-like structure compared to whole gel contractions in mixed in gels. Finally, when multiple cells were mixed prior to seeding, heterogeneous toroids formed with some containing clusters of cells.

The cardioprotective role of a neuropeptide, alpha-calcitonin gene related peptide (αCGRP), has been established in a variety of cardiovascular diseases. To increase the bioavailability of the circulating peptide, we created a peptide delivery system by encapsulating αCGRP in an alginate biopolymer and showed that subcutaneous delivery of alginate-αCGRP microcapsules (αCGRP dose= 6 mg/kg/mouse) on alternate days, up to 28 days, significantly protected hearts at pathophysiological levels in a transverse aortic constriction (TAC) pressure-overload induced heart failure murine model. The present study was performed to determine if weekly subcutaneous delivery of alginate-αCGRP microcapsules exhibited similar cardioprotective effects in TAC-mice as observed in our previous study with alternate days dose delivery scheme. This study is crucial to shed light on the efficacy of these microcapsules. An electrospray method was used to prepare alginate-αCGRP microcapsules of 200 μm diameter. Male C57BL6 mice were divided into four groups (3 mice/group): i- sham, ii- sham-alginate-CGRP, iii- TAC, and iv- TAC-alginate-CGRP. Mice from TAC and TAC-alginate-CGRP groups underwent TAC procedure. Two days post-TAC, alginate-αCGRP microcapsules (αCGRP dose= 6 mg/kg/mouse) were administered subcutaneously once a week, up to 4 weeks, in the respective alginate-CGRP groups of mice. Short-axis echocardiography was performed to evaluate cardiac functions. After 28 days of microcapsules delivery, calculated percent fractional shortening (FS) and ejection fraction (EF) in mice were (in ±SD)- sham: FS= 47.6 ± 0.9, EF= 79.8 ± 0.9; sham-alginate-CGRP: FS= 47.3 ± 1.9, EF= 79.1 ± 2; TAC: FS= 34.1 ± 4.7, EF= 63.6 ± 7.1; TAC-alginate-CGRP: FS= 32.2 ± 2.3, EF= 61.0 ± 3.4. These echo data demonstrate that TAC heart failure mice had the usual significantly reduced cardiac functions, however weekly delivery of alginate-αCGRP microcapsules showed no improvement in heart performance in the TAC-mice. Combined results from our present and previous studies suggested that alginate-αCGRP microcapsules delivery on alternate days, but not weekly, is the most efficacious choice to achieve cardioprotective effects of αCGRP against pressure-induced heart failure in mice.

Alpha-calcitonin gene related peptide (α-CGRP) is a promising neuropeptide for the treatment of cardiovascular disease. We have developed an alginate biomaterial-based delivery system which increases the peptide’s bioavailability and have shown that subcutaneous delivery of alginate-CGRP microcapsules significantly improved cardiac function in pressure overload-induced heart failure in mice. The goal of this study is to develop efficient alginate microcapsule formulations for oral delivery of α-CGRP. An electrospray method was used to prepare four different formulations of alginate-CGRP microcapsules all of 200 μm diameter- i)- alginate-CGRP microcapsules, ii)- alginate-CGRP microcapsules with UV-light exposure, iii)- poly-L-ornithine (PLO) coated alginate-CGRP microcapsules, and iv)- PLO alginate-CGRP microcapsules with UV-light exposure. The stability of the microcapsules in the digestive tract was evaluated in deionized water, simulated gastric fluid (SGF; pH 1.2), and simulated intestinal fluid (SIF; pH 6.8). Over time, the size of all four microcapsule formulations remained almost unchanged in SGF, however all four of the microcapsule formulations swelled in presence of SIF. Compared to deionized water, the size of alginate-CGRP microcapsules after 6 h incubation in SIF increased by 1.7 fold. Since all four formulations yielded similar results, we chose to further study the alginate-CGRP microcapsules in vivo . To determine the bioactive nature of the released peptide, alginate microcapsules containing α-CGRP in doses of 1, 3, and 10 (mg/kg b.wt) were fed to male C57BL/6 mice via oral gavage. Systolic blood pressure (SBP) was subsequently measured by a tail-cuff method. α-CGRP microcapsules reduced SBP in a time-dependent manner. Alginate-CGRP at 1 and 3 mg/kg lowered the SBP by 25 mmHg for up to 4 h and 48 h, respectively. However, 10 mg/kg alginate-CGRP initially reduced SBP to undetectable levels which ultimately returned to baseline level by day 7. These studies indicate that alginate microcapsules can withstand the low pH of the stomach and the release of the peptide is bioactive in vivo . Thus, alginate microcapsules may provide an ideal formulation to deliver α-CGRP orally for the long-term treatment of cardiac diseases.

Background: α-CGRP (alpha-calcitonin gene related peptide) is a cardioprotective neuropeptide. Our recent study demonstrated that the administration of native α-CGRP, using osmotic mini-pumps, protected against transverse aortic constriction (TAC) pressure-induced heart failure in mice. However, the short half-life of peptides and the non-applicability of osmotic pumps in humans limits the use of α-CGRP as a therapeutic agent for heart failure (HF). Here, we sought to comprehensively study a novel α-CGRP delivery system using alginate microcapsules to determine its bioavailability in vivo and to test for cardioprotective effects in HF mice. Methods: Native α-CGRP filled alginate microcapsules (200 µm diameter) were prepared using an electrospray method. The prepared alginate-α-CGRP microcapsules were incubated with rat cardiac H9c2 cells, mouse cardiac HL-1 cells, and human umbilical vein endothelial cells (HUVECs), and the cytotoxicity of the alginate-α-CGRP microcapsules was measured by a trypan-blue cell viability assay and a calcium dye fluorescent based assay. The efficacy of the alginate-α-CGRP microcapsules was tested in a TAC-pressure overload mouse model of heart failure. Male C57BL6 mice were divided into four groups: sham, sham-alginate-α-CGRP, TAC-only, and TAC-alginate-α-CGRP, and the TAC procedure was performed in the TAC-only and TAC-alginate-α-CGRP groups of mice to induce pressure-overload heart failure. After 2 or 15 days post-TAC, alginate-α-CGRP microcapsules (containing an α-CGRP dose of 6 mg/kg/mouse) were administered subcutaneously on alternate days, for 28 days, and echocardiography was performed weekly. After 28 days of peptide delivery, the mice were sacrificed and their hearts were collected for histological and biochemical analyses. Results: Our in vitro cell culture assays showed that alginate-α-CGRP microcapsules did not affect the viability of the cell lines tested. The alginate-α-CGRP microcapsules released their peptides for an extended period of time. Our echocardiography, biochemical, and histology data from HF mice demonstrated that the administration of alginate-α-CGRP microcapsules significantly improved all cardiac parameters examined in TAC-mice. When compared to sham mice, TAC significantly decreased cardiac functions (as determined by fraction shortening and ejection fraction) and markedly increased heart and lung weight, left ventricle (LV) cardiac cell size, cardiac apoptosis, and oxidative stress. In contrast, the administration of alginate-α-CGRP microcapsules significantly attenuated the increased heart and lung weight, LV cardiac cell size, apoptosis, and oxidative stress in TAC mice. Conclusion: Our results demonstrate that the encapsulation of α-CGRP in an alginate polymer is an effective strategy to improve peptide bioavailability in plasma and increase the duration of the therapeutic effect of the peptide throughout the treatment period. Furthermore, alginate mediates α-CGRP delivery, either prior to the onset or after the initiation of the symptom progression of pressure-overload, improves cardiac function, and protects hearts against pressure-induced HF.

Collagen fibers are essential structural components of mitral valve leaflets, their tension apparatus (chordae tendineae), and the associated papillary muscles. Excess or lack of collagen fibers in the extracellular matrix (ECM) in any of these structures can adversely affect mitral valve function. The organization of collagen fibers provides a sophisticated framework that allows for unidirectional blood flow during the precise opening and closing of this vital heart valve. Although numerous ECM molecules are essential for the differentiation, growth, and homeostasis of the mitral valve (e.g., elastic fibers, glycoproteins, and glycans), collagen fibers are key to mitral valve integrity. Besides the inert structural components of the tissues, collagen fibers are dynamic structures that drive outside-to-inside cell signaling, which informs valvular interstitial cells (VICs) present within the tissue environment. Diversity of collagen family members and the closely related collagen-like triple helix-containing proteins found in the mitral valve, will be discussed in addition to how defects in these proteins may lead to valve disease.

Studies of in vivo structures have been made possible through ex vivo cell culture systems. While two‐dimensional (2D) systems have long provided inexpensive means to test functionality of cells, three‐dimensional (3D) systems have been found to be more advantageous in providing accurate physiological response (i.e. in vivo tissue formation, increased differentiation, reduced proliferation, etc). One such technology that allows for a widely tunable extracellular matrix (ECM) is a hydrogel. Hydrogels have been proven useful in the advancements of drug delivery and tissue repair and engineering while also providing a solid molecular scaffold for cellular system modeling. Previously, our lab has observed a novel physiological response when cells were placed on top of a Collagen I hydrogel. Cells became long and thin while migrating on and through the hydrogel to form a ring‐like structure, a toroid. Interestingly, the developing toroid takes the shape of the well in which its formed. A toroid was not formed, however, with cells mixed into the hydrogel. In this case, there was an observed scaffold contraction with cells remaining uniformly distributed. Our recent studies expand on these findings by modeling cell:cell and cell:ECM interactions through the creation of single‐ and multi‐cellular environments within different hydrogel matrices. To date, we have used 9 formulations of matrices including three types of Collagen I (PureCol, Nutrigen, and Fibricol), Collagen III, Collagen V, Rat Tail Collagen, and three types of synthetic matrices (AlphaBioGel, Matrigel, and VitroGel3D) and used no less than 10 cell types including cancer cells, cardiac fibroblasts (NHFs), microvascular endothelial cells, and several types of stem cells (ADSCs).Each hydrogel was prepared using a different, optimized protocol for the specific matrices used. Matrix solution was placed in a 96 well plate (100μL/well) and 50,000 cells in media were placed on top of each stabilized gel. Gels were incubated at 37 °C for 24 hours. They were then fixed in 2% Paraformaldehyde (PFA) prior to immunofluorescence staining.A toroid is a structure created by cells cultured on top of a hydrogel. In our studies, all combinations of cell:cell:gel produced toroids except for various cancer cell lines (cells stayed spread through the hydrogel). When cells were cultured on Collagen V, no toroids were formed and the matrix was remodeled by cells, and VitroGel3D, carbohydrate matrix produced a scaffold containing cell clumps. The size of the toroids varied depending on the matrix which cells were cultured on. This suggests the possibility for optimizing the application for various protocols. Interestingly, when NHFs and ADSCs were co‐cultured on the same PureCol hydrogel, the ADSCs created florets within the toroid which was not observed in other multi‐cellular toroids. Confocal imaging showed cellular interactions in response to other cells and the changing ECM of hydrogels. Using this model of cellular interactions and programming, we can examine and explore [1] the understanding of early embryonic development and [2] the optimization of hydrogels for in vivo applications.Support or Funding InformationSPARC graduate research grant, Cook Biotech, FirstString Research Inc, NIH 2 P20‐RR016434‐06, NIH INBRE grant for South Carolina P20GM103499, R01 HL126747.

An abstract is not available for this content so a preview has been provided. As you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Many current therapeutics under development for diseases of the posterior pole of the eye are biologics. These drugs need to be administered frequently, typically via intravitreal injections. Encapsulated cells expressing the biologic of choice are becoming a tool for local protein production and release (e.g., via long-term drug delivery). In addition, encapsulation systems utilize permeable materials that allow diffusion of nutrients, waste, and therapeutic factors into and out of cells. This occurs while masking the cells from the host immune response, avoiding the need for suppression of the host immune system. This protocol describes the use of alginate as a polymer in microencapsulation coupled with the electrospray method as a microencapsulation technique. ARPE-19 cells, a spontaneously arising human RPE cell line, has been used in long-term cell therapy experiments due to its lifetime functionality, and it is used here for encapsulation and delivery of the capsules to mouse eyes. The manuscript summarizes the steps for cell microencapsulation, quality control, and ocular delivery.