Adventitial Drug Delivery of Dexamethasone to Improve Primary Patency in the Treatment of Superficial Femoral and Popliteal Artery Disease

Macrophages in cardiovascular diseases: molecular mechanisms and therapeutic targets

The immune response holds a pivotal role in cardiovascular disease development. As multifunctional cells of the innate immune system, macrophages play an essential role in initial inflammatory response that occurs following cardiovascular injury, thereby inducing subsequent damage while also facilitating recovery. Meanwhile, the diverse phenotypes and phenotypic alterations of macrophages strongly associate with distinct types and severity of cardiovascular diseases, including coronary heart disease, valvular disease, myocarditis, cardiomyopathy, heart failure, atherosclerosis and aneurysm, which underscores the importance of investigating macrophage regulatory mechanisms within the context of specific diseases. Besides, recent strides in single-cell sequencing technologies have revealed macrophage heterogeneity, cell-cell interactions, and downstream mechanisms of therapeutic targets at a higher resolution, which brings new perspectives into macrophage-mediated mechanisms and potential therapeutic targets in cardiovascular diseases. Remarkably, myocardial fibrosis, a prevalent characteristic in most cardiac diseases, remains a formidable clinical challenge, necessitating a profound investigation into the impact of macrophages on myocardial fibrosis within the context of cardiac diseases. In this review, we systematically summarize the diverse phenotypic and functional plasticity of macrophages in regulatory mechanisms of cardiovascular diseases and unprecedented insights introduced by single-cell sequencing technologies, with a focus on different causes and characteristics of diseases, especially the relationship between inflammation and fibrosis in cardiac diseases (myocardial infarction, pressure overload, myocarditis, dilated cardiomyopathy, diabetic cardiomyopathy and cardiac aging) and the relationship between inflammation and vascular injury in vascular diseases (atherosclerosis and aneurysm). Finally, we also highlight the preclinical/clinical macrophage targeting strategies and translational implications.

Liquid Drug Delivery Approaches for the Treatment of Occlusive Arterial Disease: A Systematic Review

OBJECTIVE

Local Liquid drug (LLD) delivery devices have recently emerged as a novel approach to treat peripheral arterial disease. This systemic review aims to identify and evaluate the clinical utility of the most commonly used delivery devices.

METHODS

A systemic review was performed using the Medical Subjects Heading terms of "drug delivery," "liquid," "local," and "cardiovascular disease" in PubMed, Google Scholar, and Scopus.

RESULTS

Four commonly used delivery devices were identified, including (1) the Bullfrog Micro-Infusion Device, (2) the ClearWay RX Catheter, (3) the Occlusion Perfusion Catheter, and (4) the Targeted Adjustable Pharmaceutical Administration. All have shown to successfully deliver liquid therapeutic into the target lesion and have exhibited favorable safety and efficacy profiles in preclinical and clinical trials. The LLD devices have the ability to treat very long or multiple lesions with a single device, providing a more economical option. The safety profile in LLD clinical studies is also favorable in view of recent concerns regarding adverse events with crystalline-paclitaxel-coated devices.

CONCLUSION

There is clear clinical evidence to support the concept of local liquid delivery to treat occlusive arterial disease.

CLINICAL IMPACT

The 'leave nothing behind' strategy has been at the forefront of the most recent innovations in the field of interventional cardiology and vascular interventions. Although drug coated balloons have overcome limitations associated with plain old balloon angioplasty and peripheral stents, recent safety concerns and cost considerations have impacted their usage. In this review, various liquid drug delivery devices are presented, showcasing their capabilities and success in both preclinical and clinical settings. These innovative liquid delivery devices, capable of targeted delivery and their ability to be re-used for multiple treatment sites, may provide solutions for current unmet clinical needs.

Acute and chronic venous occlusion

This review article provides an overview of acute and chronic venous occlusion, a condition that can cause significant morbidity and mortality if not diagnosed and treated promptly. The article begins with an introduction to the anatomy of the venous system, followed by a discussion of the causes and clinical features of venous occlusion. The diagnostic tools available for the assessment of venous occlusion, including imaging modalities such as ultrasound, CT, and MRI, are then discussed, along with their respective advantages and limitations. The article also covers the treatment options for acute and chronic venous occlusion, including anticoagulant therapy and endovascular interventions. This review aims to provide radiologists with an updated understanding of the pathophysiology, diagnosis, and management of acute and chronic venous occlusion.

Endovascular transmural access to carotid artery perivascular tissues: safety assessment of a novel technique

BACKGROUND

Recent advances in endovascular devices have allowed access and targeting of perivascular tissues of the peripheral circulation. The perivascular tissues of the cervical and cranial circulations have many important structures of clinical significance, yet the feasibility and safety of such an approach has not been demonstrated.

OBJECTIVE

To evaluate the safety of a novel endovascular transmural approach to target the perivascular tissues of the common carotid artery in swine.

METHODS

A micro-infusion device was positioned in the carotid arteries of three Yorkshire pigs (six carotid arteries in total), and each carotid artery was punctured 10 times in the same location to gain access to the perivascular tissues. Digital subtraction angiography was used to evaluate vessel injury or contrast extravasation. MRI and MR angiography were used to evaluate evidence of cerebral ischemia or vessel injury. Post-mortem tissue analysis was performed to assess the level of extravascular hematoma and intravascular dissection.

RESULTS

None of the tested carotid arteries showed evidence of vessel injury (dissection or perforation) or intravascular thrombosis. MRI performed after repeated puncture was negative for neck hematoma and brain ischemia. Post-mortem tissue analysis of the carotid arteries showed mild adventitial staining with blood, but without associated hematoma and without vessel dissection.

CONCLUSION

Repeated puncture of the carotid artery to gain access to the perivascular tissues using a novel endovascular transmural approach is safe in a swine model. This represents a novel approach to various tissues in close proximity to the cervical and cranial vasculature.

Clinical Potential of Hydrogen Sulfide in Peripheral Arterial Disease

Peripheral artery disease (PAD) affects more than 230 million people worldwide. PAD patients suffer from reduced quality of life and are at increased risk of vascular complications and all-cause mortality. Despite its prevalence, impact on quality of life and poor long-term clinical outcomes, PAD remains underdiagnosed and undertreated compared to myocardial infarction and stroke. PAD is due to a combination of macrovascular atherosclerosis and calcification, combined with microvascular rarefaction, leading to chronic peripheral ischemia. Novel therapies are needed to address the increasing incidence of PAD and its difficult long-term pharmacological and surgical management. The cysteine-derived gasotransmitter hydrogen sulfide (H₂S) has interesting vasorelaxant, cytoprotective, antioxidant and anti-inflammatory properties. In this review, we describe the current understanding of PAD pathophysiology and the remarkable benefits of H₂S against atherosclerosis, inflammation, vascular calcification, and other vasculo-protective effects.

Adventitial injection of HA/SA hydrogel loaded with PLGA rapamycin nanoparticle inhibits neointimal hyperplasia in a rat aortic wire injury model

Neointimal hyperplasia is a persistent complication after vascular interventions, and it is also the leading cause of vascular graft restenosis and failure after arterial interventions, so novel treatment methods are needed to treat this complication. We hypothesized that adventitial injection of HA/SA hydrogel loaded with PLGA rapamycin nanoparticle (hydrogel-PLGA-rapamycin) could inhibit neointimal hyperplasia in a rat aortic wire injury model. The HA/SA hydrogel was fabricated by the interaction of hyaluronic acid (HA), sodium alginate (SA), and CaCO₃; and loaded with PLGA rapamycin nanoparticle or rhodamine uniformly. A SD rat aortic wire injury induced neointimal hyperplasia model was developed, the control group only received wire injury, the adventitial application group received 10 μL hydrogel-PLGA-rapamycin after wire injury, and the adventitial injection group received 10 μL hydrogel-PLGA-rapamycin injected into the aortic adventitia after wire injury. Tissues were harvested at day 21 and analyzed by histology and immunohistochemical staining. Hydrogel loaded with rhodamine can be successfully injected into the aortic adventitia and was encapsuled by the adventitia. The hydrogel could be seen beneath the adventitia after adventitial injection but was almost degraded at day 21. There was a significantly thinner neointima in the adventitial application group and adventitial injection group compared to the control group (p = 0.0009). There were also significantly fewer CD68⁺ (macrophages) cells (p = 0.0012), CD3⁺ (lymphocytes) cells (p = 0.0011), p-mTOR⁺ cells (p = 0.0019), PCNA⁺ cells (p = 0.0028) in the adventitial application and adventitial injection groups compared to the control group. The endothelial cells expressed arterial identity markers (Ephrin-B2 and dll-4) in all these three groups. Adventitial injection of hydrogel-PLGA-rapamycin can effectively inhibit neointimal hyperplasia after rat aortic wire injury. This may be a promising drug delivery method and therapeutic choice to inhibit neointimal hyperplasia after vascular interventions.

Temsirolimus Adventitial Delivery to Improve ANGiographic Outcomes Below the Knee

BACKGROUND

Current endovascular treatments of below the knee (BTK) popliteal or tibial/peroneal arteries including investigational drug-coated balloons have limited long-term efficacy.

OBJECTIVES

This Phase 2 trial assessed the feasibility of adventitial deposition of temsirolimus to reduce neointimal hyperplasia and clinically relevant target lesion failure (CR-TLF) 6 months after BTK arterial revascularization.

METHODS

This prospective, multicenter, double-blinded, comparative, dose-escalation trial enrolled 61 patients with Rutherford 3 to 5 symptoms undergoing endovascular revascularization of ≥1 angiographically significant BTK lesions. Perivascular infusion after completion of arterial revascularization was randomized into control (saline) vs low-dose (0.1 mg/mL) temsirolimus groups for the first 30 patients. In the second part of the trial, patients were randomized to control versus high-dose (0.4 mg/mL) temsirolimus groups. Primary and secondary efficacy endpoints were target lesion (TL) transverse-view vessel area loss percentage (TVAL%) and CR-TLF at 6 months, respectively. CR-TLF was defined as a composite of ischemia-driven major amputation of the target limb, clinically driven target lesion revascularization (CD-TLR), and clinically relevant TL occlusion. The primary safety endpoint was freedom from major adverse limb events or perioperative death (MALE+POD) at 30 days.

RESULTS

There was no discernable difference in effect between temsirolimus doses; therefore, the low- and high-dose cohorts were pooled for the analyses. The principal analysis on the per protocol (PP) group of 53 patients revealed superior primary efficacy of the treatment arm, with reduction in TVAL% of 13.9% absolute (37.3% relative) and the rate of CR-TLF reduced by 27.1% absolute (51.3% relative), at 6 months. Subgroup analysis of all Trans-Atlantic Inter-Society Consensus (TASC) B to D lesions (N=36) revealed TVAL% reduction of 22.3% absolute (48.3% relative) and the rate of CR-TLF reduced by 39.2% absolute (56.6% relative). Freedom from 30-day MALE+POD was 100% in all groups.

CONCLUSIONS

This hypothesis-generating trial suggests that adventitial infusion of temsirolimus in BTK arteries improves TVAL% and CR-TLF with no adverse safety signals through 6 months, supporting the move to a Phase 3 trial.

CLINICAL IMPACT

There remain gaps in the endovascular treatment of patients with atherosclerotic lesions of below-the-knee (BTK) arteries. The TANGO trial evaluated the use of sub-adventitial temsirolimus with the Bullfrog micro-infusion device during BTK interventions. The therapy was safe and effective. Compared with controls, vessel lumen area patency was improved, and target lesion failure was less frequent. The effects were most appreciable in subjects with higher baseline TASC lesions (B, C, or D). Sub-adventitial temsirolimus offers the potential to improve the results of BTK interventions in this challenging patient population.

State-of-the-Art Endovascular Therapies for the Femoropopliteal Segment: Are We There Yet?

Peripheral arterial disease is an increasingly prevalent condition with significant associated morbidity, mortality, and health care expenditure. Endovascular interventions are appropriate for most patients with either ongoing symptoms of intermittent claudication despite lifestyle and medical optimization or chronic limb-threatening ischemia. The femoropopliteal segment is the most common arterial culprit responsible for claudication and the most commonly revascularized segment. Endovascular approaches to revascularization of the femoropopliteal segment are advancing with an evolving landscape of techniques for arterial access, device-based therapies, vessel preparation, and intraprocedural imaging. These advances have been marked by debate and controversy, notably related to the safety of paclitaxel-based devices and necessity of atherectomy. In this review, we provide a critical overview of the current evidence, practice patterns, emerging evidence, and technological advances for endovascular intervention of the femoropopliteal arterial segment.

Adhesive hydrogel wrap loaded with Netrin-1-modified adipose-derived stem cells: An effective approach against periarterial inflammation after endovascular intervention

Endovascular interventions, such as balloon dilation and stent implantation, are currently recommended as the primary treatment for patients with peripheral artery disease (PAD), greatly improving patient prognosis. However, the consequent lumen restenosis that occurs after endovascular interventions has become an important clinical problem. Inflammation has been proven to be crucial to postoperative restenosis. In previous studies we have identified that Netrin-1-modified adipose-derived stem cells (N-ADSCs) transplantation is an effective anti-inflammatory strategy to repair vascular damage. Nevertheless, it remained to be explored how one could constantly deliver N-ADSCs onto damaged arteries. Therefore, we developed an adhesive double network (DN) hydrogel wrap loaded with N-ADSCs for sustained perivascular delivery. Inspired by the adhesion mechanism of mussels, we developed an adhesive and tough polyacrylamide/calcium-alginate/reduced graphene oxide/polydopamine (PAM/CA/rGO/PDA) hydrogel. Dopamine was attached to graphene sheets and limitedly oxidized to generate free catechol groups. The hydrogel could wrap damaged arteries and induce anti-inflammatory effects through N-ADSCs. In vitro experiments demonstrated that N-ADSCs significantly promoted the M2 polarization of macrophages to anti-inflammatory phenotypes and reduced the expression of inflammatory factors. In vivo experiments in a rat carotid artery guidewire injury model showed that the adhesive hydrogel wrap loaded with N-ADSCs could significantly reduce arterial inflammation, inhibit intimal hyperplasia and improve re-endothelialization. Altogether, this newly developed N-ADSCs-loaded hydrogel wrap provides an effective slow-releasing system, which may be a promising way to prevent and treat restenosis after endovascular interventions.

Pharmacological prevention of intimal hyperplasia: A state-of-the-art review

Intimal hyperplasia (IH) occurs in a considerable number of cases of blood vessel reconstruction by stenting or balloon angioplasty, venous bypass grafting, and arteriovenous dialysis accesses. It is triggered by endothelial injury during the vascular intervention and leads to vessel restenosis with life-threatening consequences for patients. To date, the drugs used for IH prevention in clinics-paclitaxel and rapalog drugs-have been focusing primarily on the vascular smooth muscle cell (VSMC) proliferation pathway of IH development. Limitations, such as endothelial toxicity and inappropriate drug administration timing, have spurred the search for new and efficient pharmacological approaches to control IH. In this state-of-the-art review, we present the pathways of IH development, focusing on the key events and actors involved in IH. Subsequently, we discuss different drugs and drug combinations interfering with these pathways based on their effect on peripheral circulation IH models in animal studies, or on clinical reports. The reports were obtained through an extensive search of peer-reviewed publications in Pubmed, Embase, and Google Scholar, with search equations composed based on five concepts around IH and their various combinations. To improve vascular intervention outcomes, rethinking of conventional therapeutic approaches to IH prevention is needed. Exploring local application of drugs and drug combinations acting on different pathophysiological pathways of IH development has the potential to provide effective and safe restenosis prevention.

Therapeutic strategies targeting inflammation and immunity in atherosclerosis: how to proceed?

Atherosclerosis is a chronic inflammatory disease of the arterial wall, characterized by the formation of plaques containing lipid, connective tissue and immune cells in the intima of large and medium-sized arteries. Over the past three decades, a substantial reduction in cardiovascular mortality has been achieved largely through LDL-cholesterol-lowering regimes and therapies targeting other traditional risk factors for cardiovascular disease, such as hypertension, smoking, diabetes mellitus and obesity. However, the overall benefits of targeting these risk factors have stagnated, and a huge global burden of cardiovascular disease remains. The indispensable role of immunological components in the establishment and chronicity of atherosclerosis has come to the forefront as a clinical target, with proof-of-principle studies demonstrating the benefit and challenges of targeting inflammation and the immune system in cardiovascular disease. In this Review, we provide an overview of the role of the immune system in atherosclerosis by discussing findings from preclinical research and clinical trials. We also identify important challenges that need to be addressed to advance the field and for successful clinical translation, including patient selection, identification of responders and non-responders to immunotherapies, implementation of patient immunophenotyping and potential surrogate end points for vascular inflammation. Finally, we provide strategic guidance for the translation of novel targets of immunotherapy into improvements in patient outcomes.

In this Review, the authors provide an overview of the immune cells involved in atherosclerosis, discuss preclinical research and published and ongoing clinical trials assessing the therapeutic potential of targeting the immune system in atherosclerosis, highlight emerging therapeutic targets from preclinical studies and identify challenges for successful clinical translation.

Inflammation is an important component of the pathophysiology of cardiovascular disease; an imbalance between pro-inflammatory and anti-inflammatory processes drives chronic inflammation and the formation of atherosclerotic plaques in the vessel wall.

Clinical trials assessing canakinumab and colchicine therapies in atherosclerotic cardiovascular disease have provided proof-of-principle of the benefits associated with therapeutic targeting of the immune system in atherosclerosis.

The immunosuppressive adverse effects associated with the systemic use of anti-inflammatory drugs can be minimized through targeted delivery of anti-inflammatory drugs to the atherosclerotic plaque, defining the window of opportunity for treatment and identifying more specific targets for cardiovascular inflammation.

Implementing immunophenotyping in clinical trials in patients with atherosclerotic cardiovascular disease will allow the identification of immune signatures and the selection of patients with the highest probability of deriving benefit from a specific therapy.

Clinical stratification via novel risk factors and discovery of new surrogate markers of vascular inflammation are crucial for identifying new immunotherapeutic targets and their successful translation into the clinic.

Influence of Drug Incorporation on the Physico-Chemical Properties of Poly(l-Lactide) Implant Coating Matrices-A Systematic Study

Local drug delivery has become indispensable in biomedical engineering with stents being ideal carrier platforms. While local drug release is superior to systemic administration in many fields, the incorporation of drugs into polymers may influence the physico-chemical properties of said matrix. This is of particular relevance as minimally invasive implantation is frequently accompanied by mechanical stresses on the implant and coating. Thus, drug incorporation into polymers may result in a susceptibility to potentially life-threatening implant failure. We investigated spray-coated poly-l-lactide (PLLA)/drug blends using thermal measurements (DSC) and tensile tests to determine the influence of selected drugs, namely sirolimus, paclitaxel, dexamethasone, and cyclosporine A, on the physico-chemical properties of the polymer. For all drugs and PLLA/drug ratios, an increase in tensile strength was observed. As for sirolimus and dexamethasone, PLLA/drug mixed phase systems were identified by shifted drug melting peaks at 200 °C and 240 °C, respectively, whereas paclitaxel and dexamethasone led to cold crystallization. Cyclosporine A did not affect matrix thermal properties. Altogether, our data provide a contribution towards an understanding of the complex interaction between PLLA and different drugs. Our results hold implications regarding the necessity of target-oriented thermal treatment to ensure the shelf life and performance of stent coatings.

New Innovations and Devices in the Management of Chronic Limb-Threatening Ischemia

As the number of patients afflicted by chronic limb-threatening ischemia (CLTI) continues to grow, new solutions are necessary to provide effective, durable treatment options that will lead to improved outcomes. The diagnosis of CLTI remains mostly clinical, and endovascular revascularization remains mostly balloon-based. Multiple innovative techniques and technologies are in development or in early usage that may provide new solutions. This review categorizes areas of advancement, highlights recent developments in the management of CLTI and looks forward to novel devices that are currently under investigation.

Current developments in endovascular therapy of peripheral vascular disease

More than 200 million people worldwide have peripheral artery disease (PAD) or its most severe manifestation, critical limb ischemia (CLI). While endovascular treatment has become first line therapy in most cases, a number of challenges remain for optimal treatment of femoropopliteal (FP) or infrapopliteal (IP) disease, especially when these lesions are severely calcified, chronic total occlusions (CTOs) or in-stent restenosis (ISR). Continued evolution of technologies has significantly improved the outcomes for endovascular treatment. A number of new devices are in the pipeline right now, including new paclitaxel eluting stents and balloons, intravascular lithotripsy to treat severely calcified lesions, adventitial delivery of anti-restenotic agents to limit restenosis rates, and percutaneous femoro-popliteal bypass.

Vascular Positron Emission Tomography and Restenosis in Symptomatic Peripheral Arterial Disease: A Prospective Clinical Study

OBJECTIVES

This study determined whether in vivo positron emission tomography (PET) of arterial inflammation (¹⁸F-fluorodeoxyglucose [¹⁸F-FDG]) or microcalcification (¹⁸F-sodium fluoride [¹⁸F-NaF]) could predict restenosis following PTA.

BACKGROUND

Restenosis following lower limb percutaneous transluminal angioplasty (PTA) is common, unpredictable, and challenging to treat. Currently, it is impossible to predict which patient will suffer from restenosis following angioplasty.

METHODS

In this prospective observational cohort study, 50 patients with symptomatic peripheral arterial disease underwent ¹⁸F-FDG and ¹⁸F-NaF PET/computed tomography (CT) imaging of the superficial femoral artery before and 6 weeks after angioplasty. The primary outcome was arterial restenosis at 12 months.

RESULTS

Forty subjects completed the study protocol with 14 patients (35%) reaching the primary outcome of restenosis. The baseline activities of femoral arterial inflammation (¹⁸F-FDG tissue-to-background ratio [TBR] 2.43 [interquartile range (IQR): 2.29 to 2.61] vs. 1.63 [IQR: 1.52 to 1.78]; p < 0.001) and microcalcification (¹⁸F-NaF TBR 2.61 [IQR: 2.50 to 2.77] vs. 1.69 [IQR: 1.54 to 1.77]; p < 0.001) were higher in patients who developed restenosis. The predictive value of both ¹⁸F-FDG (cut-off TBR_max value of 1.98) and ¹⁸F-NaF (cut-off TBR_max value of 2.11) uptake demonstrated excellent discrimination in predicting 1-year restenosis (Kaplan Meier estimator, log-rank p < 0.001).

CONCLUSIONS

Baseline and persistent femoral arterial inflammation and micro-calcification are associated with restenosis following lower limb PTA. For the first time, we describe a method of identifying complex metabolically active plaques and patients at risk of restenosis that has the potential to select patients for intervention and to serve as a biomarker to test novel interventions to prevent restenosis.

Adventitial injection delivery of nano-encapsulated sirolimus (Nanolimus) to injury-induced porcine femoral vessels to reduce luminal restenosis

Endovascular therapy in peripheral intervention has grown exponentially in the past decade, but the issue of high restenosis rates in lower extremity arteries still persist. While drug-coated balloons (DCB) have been the device of choice, recent controversary regarding the long-term safety of paclitaxel have raised concern over current DCBs. In our study, we proposed that the direct injection of a sirolimus nanoliposomal formulation (Nanolimus) using a infusion catheter can attenuate inflammation response in injured vessels. In vitro characterization showed retention of the nanoliposomes size and detectable drug amount up to 336 days in storage. For in vivo study, four female, mixed breed swines were subjected to balloon injury of the femoral arteries before treatment with either injection of saline (n = 4) or Nanolimus (n = 12) using the Bullfrog catheter. Pharmacokinetic analysis demonstrated sustained sirolimus release in the arteries and undetectable systemic drug level at 28 days. Arteries treated with Nanolimus showed significant reduction in neointima area (0.2 ± 0.3 mm² vs 2.0 ± 1.2 mm², p < 0.01) and luminal stenosis (14.2 ± 7.2% vs. 67.7 ± 24.8%, p < 0.01) compared to controls. In summary, adventitial delivery of sirolimus using an infusion catheter is a feasible and safe method to reduce vascular restenosis.

Magnetic nano carboxymethyl cellulose-alginate/chitosan hydrogel beads as biodegradable devices for controlled drug delivery

For the first time, nano carboxymethyl cellulose (NCMC) was synthesized via cellulose nanocrystal carboxymethylation. This nanomaterial was magnetized and used in bilayer alginate-chitosan hydrogel beads formulation to develop eco-friendly, smart, and magnetic sensitive hydrogel beads for the controlled pH-sensitive release of dexamethasone as a model drug. Water-soluble nanocrystalline cellulose (NCMC) and bilayer hydrogel beads were characterized in terms of size, surface morphology, surface modification, crystallinity, drug loading content, and in vitro drug release profile using various technics. Furthermore, the swelling behavior of hydrogels was examined and reported in three buffer media. The NCMCs improved drug loading capacity and swelling properties and also regulated drug release behavior of hydrogels. The hydrogel beads swelling specification exhibited a higher index in phosphate buffer at pH 5.8 than at pH 1.2 and 7.4. Besides, in vitro release of beads revealed excellent pH-sensitive drug release profiles and prevented release in the gastrointestinal tract. The beads showed high pH sensitivity for dexamethasone drug in pH 5.8 in compared to other pH media. The obtained results could introduce hydrogel beads as a high potential drug delivery system.