Bugra Ayan

• Doctor of Philosophy
• PostDoc Position at Stanford University

Three-dimensional (3D) bioprinting is an appealing approach for building tissues; however, bioprinting of mini-tissue blocks (i.e., spheroids) with precise control on their positioning in 3D space has been a major obstacle. Here, we unveil “aspiration-assisted bioprinting (AAB),” which enables picking and bioprinting biologics in 3D through harness...

Statement of significance: Biofabrication of living tissues and organs at the clinically-relevant volumes vitally depends on the integration of vascular network. Despite the great progress in traditional biofabrication approaches, building perfusable hierarchal vascular network is a major challenge. Bioprinting is an emerging technology to fabrica...

Statement of significance: Present advances in tissue biofabrication have crucial role to play in aiding the pharmaceutical development process achieve its objectives. Advent of three-dimensional (3D) models, in particular, is viewed with immense interest by the community due to their ability to mimic in vivo hierarchical tissue architecture and h...

On-chip microparticle and cell coating technologies enable a myriad of applications in chemistry, engineering, and medicine. Current microfluidic coating technologies often rely on magnetic labeling and concurrent deflection of particles across laminar streams of chemicals. Herein, we introduce an acoustofluidic approach for microparticle and cell...

Idiopathic pulmonary fibrosis (IPF) is a fatal, progressive lung disease characterized by extensive scarring and thickening of lung tissue that leads to respiratory failure. Early and accurate diagnosis is crucial for monitoring disease progression and assessing therapeutic efficacy. While imaging modalities such as radiological X-rays and high-res...

The disease of osteoporosis is characterized by impaired bone structure and an increased risk of fractures. There is a significant impact of cytokines and hormones on bone homeostasis and the diagnosis of osteoporosis. As defined by the World Health Organization (WHO), osteoporosis is defined as having a bone mineral density (BMD) that is 2.5 stand...

Microgravity has been shown to lead to both muscle atrophy and impaired muscle regeneration. The purpose was to study the efficacy of microgravity to model impaired muscle regeneration in an engineered muscle platform and then to demonstrate the feasibility of performing drug screening in this model. Engineered human muscle was launched to the Inte...

Hospitalized patients with indwelling catheters face the threat of catheter-associated infections (CAIs), which often lead to high morbidity and mortality rates. Disinfection procedures including metal-based antibacterial coatings and photosensitive nanoparticles are unsatisfactory due to concerns associated with long-term toxicity. This study inve...

The vulnerability of skin wounds has made efficient wound dressing a challenging issue for decades, seeking to mimic the natural microenvironment of cells to facilitate cell binding, augmentation, and metamorphosis. Many three-dimensional (3D) bioprinted hydrogel-based configurations have been developed using high-tech devices to overcome the limit...

Three-dimensional (3D) bioprinting of cellular or biological components are an emerging field to develop tissue structures that mimic the spatial, mechanochemical and temporal characteristics of cardiovascular tissues. 3D multi-cellular and multi-domain organotypic biological constructs can better recapitulate in vivo physiology and can be utilized...

Volumetric muscle loss (VML) is associated with irreversibly impaired muscle function due to traumatic injury. Experimental approaches to treat VML include the delivery of basic fibroblast growth factor (bFGF) or rehabilitative exercise. The objective of this study was to compare the effects of spatially nanopatterned collagen scaffold implants wit...

Three-dimensional (3D) printing technology is increasingly being employed in biochemical as well as clinical applications and more importantly in fabrication of microfluidic devices. However, the microfluidic community mainly relies on photolithography for fabrication of a defined mask, which is both tedious and expensive requiring clean room setti...

Metastatic breast cancer is one of the deadliest forms of malignancy, primarily driven by its characteristic micro‐environment comprising cancer cells interacting with stromal components. These interactions induce genetic and metabolic alterations creating a conducive environment for tumor growth. In this study, a physiologically relevant 3D vascul...

Annually increasing incidences of cardiac-related disorders and cardiac tissue's minimal regenerative capacity have motivated the researchers to explore effective therapeutic strategies. In the recent years, bioprinting technologies have witnessed a great wave of enthusiasm and have undergone steady advancements over a short period, opening the pos...

Conventional top-down approaches in tissue engineering involving cell seeding on scaffolds have been widely used in bone engineering applications. However, scaffold-based bone tissue constructs have had limited clinical translation due to constrains in supporting scaffolds, minimal flexibility in tuning scaffold degradation, and low achievable cell...

The heterogeneous and anisotropic articular cartilage is generally studied as a layered structure of “zones” with unique composition and architecture, which is difficult to recapitulate using current approaches. A novel hybrid bioprinting strategy is presented here to generate zonally stratified cartilage. Scaffold‐free tissue strands (TSs) are mad...

The heterogeneous and anisotropic articular cartilage is generally studied as a layered structure of “zones” with unique composition and architecture, which is difficult to recapitulate using current approaches. A novel hybrid bioprinting strategy is presented here to generate zonally stratified cartilage. Scaffold‐free tissue strands (TSs) are mad...

Bioprinting of cellular aggregates, such as tissue spheroids, to form three-dimensional (3D) complex-shaped arrangements, has posed a major challenge due to lack of robust, reproducible and practical bioprinting techniques. Here, we demonstrate 3D aspiration-assisted freeform bioprinting of tissue spheroids by precisely positioning them in self-hea...

Osteochondral defects contain damage to both the articular cartilage and underlying subchon- dral bone, which remains a significant challenge in orthopedic surgery. Layered structure of bone, cartilage and the bone-cartilage interface must be taken into account in the case of biofabrication of the osteochondral (OC) interface. In this study, a dual...

Conventional top-down approaches in tissue engineering involving cell seeding on scaffolds have been widely used in bone engineering applications. However, scaffold-based bone tissue constructs have had limited clinical translation due to constrains in supporting scaffolds, minimal flexibility in tuning scaffold degradation, and low achievable cell...

Bioprinting of cellular aggregates, such as tissue spheroids or organoids, in complex three-dimensional (3D) arrangements has been a major obstacle for scaffold-free fabrication of tissues and organs. In this research, we unveiled a new approach to the bioprinting of tissue spheroids in a yield stress granular gel, which exhibited unprecedented cap...

Extrusion-based bioprinting of hydrogels in a granular secondary gel enables the fabrication of cell-laden three-dimensional (3D) constructs in an anatomically accurate manner, which is challenging using conventional extrusion-based bioprinting processes. In this study, carbohydrazide-modified gelatin (Gel-CDH) was synthesized and deposited into a...

Current technologies for manufacturing of microfluidic devices include soft-lithography, wet and dry etching, thermoforming, micro-machining and three-dimensional (3D) printing. Among them, soft-lithography has been the mostly preferred one in medical and pharmaceutical fields due to its ability to generate polydimethylsiloxane (PDMS) devices with...

Introduction: Although there have been significant contributions from the pharmaceutical industry to clinical practice, several diseases remain unconquered, with the discovery of new drugs remaining a paramount objective. The actual process of drug discovery involves many steps including pre-clinical and clinical testing, which are highly time- and...

Background:. Hernia repair is a common surgical procedure with polypropylene (PP) mesh being the standard material for correction because of its durability. However, complications such as seroma and pain are common, and repair failures still approach 15% secondary to poor tissue integration. In an effort to enhance mesh integration, we evaluated th...

Three-dimensional (3D) organoids have shown advantages in cell culture over traditional two-dimensional (2D) culture, and have great potential in various applications of tissue engineering. However, there are limitations in current organoid fabrication technologies, such as uncontrolled size, poor reproductively, and inadequate complexity of organo...

Despite the recent achievements in cell-based therapies for curing type-1 diabetes (T1D), capillarization in beta (β)-cell clusters is still a major roadblock as it is essential for long-term viability and function of β-cells in vivo. In this research, we report sprouting angiogenesis in engineered pseudo islets (EPIs) made of mouse insulinoma βTC3...

Despite extensive use of polydimethylsiloxane (PDMS) in medical applications, such as lab-on-a-chip or tissue/organ-on-a-chip devices, point-of-care devices and biological machines, the manufacturing of PDMS devices is limited to soft-lithography and its derivatives, which prohibits the fabrication of geometrically complex shapes. With the recent a...

Background Hernia repair is a common surgical procedure with mesh often used. Current mesh materials have a high incidence of repair failures, due to poor tissue integration, and complications such as seroma and pain. Polypropylene (PP) mesh is the standard material in hernia repair secondary to its material durability; however, failures still appr...

Craniofacial (CF) tissue is an architecturally complex tissue consisting of both bone and soft tissues with significant patient specific variations. Conditions of congenital abnormalities, tumor resection surgeries, and traumatic injuries of the CF skeleton can result in major deficits of bone tissue. Despite advances in surgical reconstruction tec...

Micro- to nanosized droplets of liquid metals, such as eutectic gallium indium (EGaIn) and Galinstan, have been used for developing a variety of applications in flexible electronics, sensors, catalysts, and drug delivery systems. Currently used methods for producing micro- to nanosized droplets of such liquid metals possess one or several drawbacks...

Sağlık kuruluşları; hastalar, hasta yakınları, çalışanlar ve ziyaretçiler için güvenli, işlevsel ve destekleyici bir tesis sunmakla yükümlüdür. Tesiste sağlanan fiziki güvenlik aynı zamanda bir kalite ölçüsüdür. Günümüzde kalite, hizmet alan kişiler için önemli bir kriter haline gelmiştir ve kalite arttırma politikasını benimsemiş olan kuruluşların...

Trombositler, kan pıhtıları ve oluşumlarında görev alan kan hücreleridir. Bu çalışmada trombositlerin pıhtılaşmadan önceki P-Selektin molekülünün ölçülmesi için daha ucuz, basit, kullanılması kolay bir QCM(Kuvars Kristal Mikrodenge) sistemi tasarlanmıştır. Trombosit aktivasyonu çeşitli yöntemlerle belirlenmektedir. QCM üzerine aktivasyon ölçümü içi...