Adam J Katz

Wake Forest University | WFU · Department of Plastic and Reconstructive Surgery

The utilization of adipose tissue has evolved from an afterthought to being considered an organ of healing. As fat grafting has progressed and grafts have continued to be further disaggregated, we find ourselves with a spectrum ranging from macrofat to nanofat. We conceptualize that along this spectrum, particle size correlates directly with the vo...

Background: There is a growing presence of literature within plastic surgery that establishes best practice for postoperative antibiotics after implant-based breast reconstruction (IBBR), although it has not been widely adopted or translated into clinical practice. This study aims to determine how antibiotic and duration affects patient outcomes....

Vascularization is essential for realizing thick and functional tissue constructs that can be utilized for in vitro study platforms and in vivo grafts. The vasculature enables the transport of nutrients, oxygen, and wastes and is also indispensable to organ functional units such as the nephron filtration unit, the blood-air barrier, and the blood-b...

Background: Increasingly patients with unilateral breast cancer elect to undergo bilateral mastectomy with subsequent reconstruction. Studies have aimed to better identify the risks associated with performing mastectomy on the noncancerous breast. Our study aims to identify differences in complications between therapeutic and prophylactic mastecto...

Background The importance of thermoregulation in surgical procedures has become a recent focus for anesthesiologists and surgeons to improve patient outcomes. In breast surgery, maintenance of normothermia has been shown to reduce surgical site infections. However, there is a paucity of information evaluating the relationship between intraoperative...

The management of breast cancer has experienced tremendous changes in the last half-century. In today’s multimodal approach to breast cancer, patients have the prospect of achieving a sense of normalcy after mastectomy thanks to advancements in oncology and breast reconstruction. Although the oncologic management of breast cancer has evolved over m...

Stromal vascular fraction (SVF), isolated from adipose tissue, identifies as a rich cell source comprised of endothelial cells, endothelial progenitor cells, pericytes, smooth muscle cells, fibroblasts, and immune cells. SVF represents a promising therapeutic heterogonous cell source for growing new blood microvessels due to its rich niche of cells...

Background In recent years, adipose-derived stromal cells (ASCs) have been heavily studied for soft tissue regeneration, augmentation, and dermal wound healing. Methods In this review, we investigated the trends in injectable scaffolds for ASC delivery in the dermis, and injectable or implantable scaffolds for ASC delivery in the subcutis. A total...

Restoration of form and function requires apposition of tissues in the form of flaps to reconstitute local perfusion. Successful reconstruction relies on flap survival and its integration with the recipient bed. The flap's precariously perfused hypoxic areas undergo adaptive microvascular changes both internally and in connection with the recipient...

Autologous fat grafting and implant surgery are used for volume restoration in plastic surgery. With the aim of producing a treatment superior to current solutions, we report a randomized, controlled, data assessor-blinded clinical trial comparing fat grafts enriched with ex vivo-expanded autologous adipose-derived stromal cells (ASCs) to nonenrich...

Background:. Autologous fat transfer—also referred to as fat grafting—has been reported to provide beneficial effects to overlying scar and skin. Despite procedural frequency, there is a paucity of high-level evidence guiding the surgeon in technique, patient selection, and efficacy. Methods:. A multicenter, double-blinded, randomized, internally p...

Pressure ulcers result in part due to ischemia reperfusion injury to the skin and present frequently in elderly or quadriplegic patients with reduced mobility. In spite of the high economic and societal cost of this condition, pressure ulcer therapy relies primarily on preventive strategies and invasive surgical intervention. A growing body of clin...

Pressure injuries/ulcers are frequent complications in elderly, paraplegic, and quadriplegic patients that account for considerable cost to the international health care economy and remain refractory to current treatment options. Autologous or allogeneic adult stromal/stem cells represent an alternative therapeutic approach. The current study exten...

Although adipose tissue and cells show considerable promise for clinical translation in the emerging field of regenerative medicine, they present a challenge to the regulatory community both nationally and internationally. This has been exacerbated by recent high-profile cases involving adverse events attributed to adipose cell-based therapies. Thi...

Angiogenesis, the growth of new vessels from pre‐existing vessels, is vital to wound healing in the cases of myocardial infarction and peripheral arterial disease. Adipose‐derived stromal vascular fraction (SVF), consisting of endothelial cells, endothelial progenitor cells, pericytes, smooth muscle cells, fibroblasts and immune cells, can be trans...

Background: Breast reconstruction with fat grafting is a new alternative to prosthetic implants and flaps for women with breast cancer. In this study, we investigate the efficacy of fat grafting for breast reconstruction in a meta-analysis. Methods: The study followed the PRISMA and MOOSE guidelines for systematic reviews and meta-analyses. Stud...

The GID SVF-1 and GID SVF-2 are closed-system, disposable, scalable cellular isolation devices designed for isolating the human adipose-derived stromal vascular fraction (hSVF) from lipoaspirates at the point-of care. The purpose of this study was to characterize the device performance with respect to cell yield and viability of the hSVF, as well a...

The clinical effectiveness of systemically-administered human mesenchymal stem cells (hMSCs) depends on their capacity to engage vascular endothelium. hMSCs derived from bone marrow (BM-hMSCs) natively lack endothelial binding capacity but express a CD44 glycovariant containing N-linked sialyllactosamines that can be α(1,3)-fucosylated using fucosy...

Methods: A total of 74 patients underwent 77 cell-enhanced fat grafting procedures to restore breast volume deficits associated with cosmetic and reconstructive indications. Although all procedures used standardized fat grafts, 21 of the fat grafts were enriched with a low dose of SVF cells and 56 were enriched with a high SVF cell dose. Three-dim...

More than 2.5 million patients in the U.S. require treatment for pressure ulcers annually, and the elderly are at particularly high risk for pressure ulcer development. Current therapy for pressure ulcers consists of conservative medical management for shallow lesions and aggressive debridement and surgery for deeper lesions. The current study uses...

"Adipose tissue is a valuable, exploitable, appealing source of regenerative cells that can be used for a variety of clinical challenges. This article reviews the history of the development of adipose-derived cell science, particularly in the context of tissue engineering and regenerative medicine. It describes some of the advancements made in the...

A method and device for creating hanging drop cell aggregates. The method and device includes a plurality of pegs that allow for high throughput culture of aggregates. Also disclosed are means of transferring formed aggregates to various destinations, such as well plates, scaffolding, tissues, or wounds. Use of the device permits aggregates to be p...

A method and device for creating hanging drop cell aggregates. The method and device includes a plurality of pegs that allow for high throughput culture of aggregates. Also disclosed are means of transferring formed aggregates to various destinations, such as well plates, scaffolding, tissues, or wounds. Use of the device permits aggregates to be p...

As the world's population lives longer, the number of individuals at risk for pressure ulcers will increase considerably in the coming decades. In developed countries, up to 18% of nursing home residents suffer from pressure ulcers and the resulting hospital costs can account for up to 4% of a nation's health care budget. Although full-thickness su...

This study evaluated the 20-year history of the American Association of Plastic Surgeons Academic Scholar Award from 1992 through 2012, to assess the program's value and justify future investment. The curricula vitae of 18 Academic Scholars who completed their award by 2012 were analyzed. Data were compiled into 5-year blocks and reviewed. Award re...

Mesenchymal cells are emerging as a promising cell platform for regenerative therapies. However, the fate of cells after transplantation in many different disease settings and tissue beds remains unclear. In this study, human adipose-derived stromal/stem (ASCs) cells were fluorescently labeled with a membrane dye and injected into both immunocompet...

The invention provides compositions and methods useful for treating wounds and enhancing wound healing, particularly for diabetic wound healing. One embodiment provides a method of treating a wound comprising administering to a subject in need thereof a therapeutically effective amount of adipose tissue derived stem cells to treat said wound, where...

Adipose-derived stem cells are an excellent multipotent stem cell candidate because they are abundant, plastic easily harvested, highly proliferative, sand are robust enough to withstand lengthy culture periods. When grown as scaffold-free three-dimensional spheroids, these benefits are amplified. The three-dimensional architecture increases the cl...

A mechano-active nanofibrous scaffold system for in vitro active cell culture is fabricated and demonstrated using electrospun nanofibers with magnetic nanoparticles embedded, and an electromagnet. The electrospun nanofiber consists of polycaprolactone and iron oxide nanoparticles. The magnetic nanofibrous membrane is held by micromachined printing...

El tejido adiposo obtenido mediante liposucción es una fuente idónea para aislar células con potencial terapéutico, las denominadas células de la fracción estromal vascular (FEV), que incluyen células madre mesenquimales. Estas células se han convertido en una de las principales herramientas de terapia celular autóloga para diversas aplicaciones mé...

The invention provides compositions and methods for preparing and characterizing multipotential mesenchymal stem cell aggregates. The invention further provides methods for using stem cell aggregates of the invention.

Background: Retinal vasculopathies, including diabetic retinopathy (DR), threaten the vision of over 100 million people. Retinal pericytes are critical for microvascular control, supporting retinal endothelial cells via direct contact and paracrine mechanisms. With pericyte death or loss, endothelial dysfunction ensues, resulting in hypoxic insult...

Adipose-derived stem cells (ADSCs) are an attractive cell source for tissue engineering, and recently a modified aggregate culture of human ADSCs (hADSCs) was established based on preparation of three-dimensional (3D) cell aggregates in growth factor-enriched low serum medium using the hanging droplet method. Growth and differentiation factor 5 (GD...

The epithelial-to-mesenchymal transition (EMT) is a de-differentiation process that has been implicated in metastasis and the generation of cancer initiating cells (CICs) in solid tumors. To examine EMT in non-small cell lung cancer (NSCLC), we utilized a three dimensional (3D) cell culture system in which cells were co-stimulated with tumor necros...

Cytokine-treated 3D A549 cells show increased fibroid and mesenchymal morphology. Monolayer (2D) and 3D A549 cultures were left alone or treated with TNF and TGFβ for ninety-six hours. Cells were subsequently disaggregated, replated on glass coverslips, and cultured for an additional eighteen hours in 2% FBS. The cells were then fixed in methanol,...

TNF and TGFβ-treated 3D A549 cells show increased RelA phosphorylation and nuclear DNA binding activity. (A) Immunoblot analysis of 3D A549 cells indicates that cells display constitutive RelA phosphorylation upon co-stimulation with both TNF and TGFβ over the three day period. (B) Nuclear extracts from cytokine-treated 3D control A549.V cells show...

QRT-PCR Primers. (DOC)

Recent advances in protein detection and analysis have lead to multiple in depth studies that analyze the adipose-derived stem cell (ASC) secretome. These studies differ significantly in their methods of secretome preparation and analysis. Most of them use a pro-differentiation or pro-inflammatory stimulus to observe differential expression of secr...

P2 hASC injections do not impact normal retinal vascularizaition. Compared to contralateral PBS injected controls (A), eyes injected with hASCs (B) at P2 and harvested at P7 (without exposure to hyperoxia) displayed no obvious differences in vascular coverage, density, or morphology. (TIF)

hBMSCs fail to accelerate hypoxic revascularization. Compared to contralateral PBS injected controls (A), eyes injected with unsorted hBMSCs (B) at P12 and harvested at P14 showed no statistical difference in rate of revascularization of the central retina at P14 (C). However, when compared to PBS contralateral controls (D), eyes injected with hASC...

Background aims: Adipose tissue is a rich and very convenient source of cells for regenerative medicine therapeutic approaches. However, a characterization of the population of adipose-derived stromal and stem cells (ASCs) with the greatest therapeutic potential remains unclear. Under the authority of International Federation of Adipose Therapeuti...

Background context: Healthy mammalian cells in normal tissues are organized in complex three-dimensional (3D) networks that display nutrient and signaling gradients. Conventional techniques that grow cells in a 2D monolayer fail to reproduce the environment that is observed in vivo. In recent years, 3D culture systems have been used to mimic tumor...

Background: Radiation therapy has a known deleterious influence on breast reconstruction. It is widely accepted that the results of irradiated breast reconstructions are, overall, cosmetically inferior, with more frequent complications. Whether there are specific aspects of radiation therapy resulting in less favorable results, however, remains co...

Acellular dermal matrices are used in a variety of reconstructive and cosmetic procedures. There seems to be host tissue integration, revascularization, and recellularization into these products, but the exact timing and differences among these remain unknown. The purpose of this study is to determine and compare these properties of 4 different ace...

Adipose-derived stromal/stem cells (ASCs) have been gaining recognition as an extremely versatile cell source for tissue engineering. The usefulness of ASCs in biofabrication is further enhanced by our demonstration of the unique properties of these cells when they are cultured as three-dimensional cellular aggregates or spheroids. As described her...

Macrophages have recently been characterized as having an M1 or M2 phenotype based on receptor expression, mechanism of activation and function. The effects of macrophage phenotype upon tissue remodeling following implantation of an acellular dermal matrix (ADM) is largely unknown. The purpose of this study was to compare the macrophage phenotype a...

After more than a decade of extensive experimentation, the promise of stem cells to revolutionize the field of medicine has negotiated their entry into clinical trial. Adipose tissue specifically holds potential as an attainable and abundant source of stem cells. Currently undergoing investigation are adipose stem cell (ASC) therapies for diabetes...

Previous studies have shown that exposure to a hypoxic in vitro environment increases the secretion of pro-angiogenic growth factors by human adipose-derived stromal cells (hASCs) [Cao Y, et al., Biochem Biophys Res Commun 332: 370-379, 2005; Kokai LE, et al., Plast Reconstr Surg 116: 1453-1460, 2005; Park BS, et al., Biomed Res (Tokyo) 31: 27-34,...

Impaired wound healing is a significant clinical, economic, and social problem. There is a growing body of research over the past several decades that supports the importance of neuropeptides and neurotransmitters in wound healing, particularly in diabetic patients. The purpose of this article is to review current translational research that suppor...

Tendon injuries range from acute traumatic ruptures and lacerations to chronic overuse injuries, such as tendinosis. Even with improved nonsurgical, surgical, and rehabilitation techniques, outcomes following tendon repair are inconsistent. Primary repair remains the standard of care. However, repaired tendon tissue rarely achieves functionality eq...

Multiple tissues can serve as a source of adult or somatic stem cells. Some of these tissues are available at only one point in the lifecycle, such as the umbilical cord, Wharton’s jelly, and placenta. In contrast, others are available throughout life and these include adipose tissue, bone marrow, and skeletal muscle. This chapter focuses on the la...

The use of autologous fat has many benefits for the correction of contour differences. It is a plentiful, non-immunogenic, and easily manipulated substance. The purpose of fat transplantation for most indications is the correction of a contour defect with predictable and long-term volume maintenance. Manipulating harvested fat in particular ways ma...

Human adipose-derived stromal cells (ASCs) have been shown to possess therapeutic potential in a variety of settings, including cutaneous wound healing; however, it is unknown whether the regenerative properties of this cell type can be applied to diabetic ulcers. ASCs collected from elective surgical procedures were used to treat full-thickness de...

The existence of fibrocartilage, bone-like tissues, nerves, and blood vessels in the anulus fibrosus during intervertebral disc degeneration has been well documented. Migration of differentiated cells from outside the intervertebral disc has been hypothesized as a possible mechanism for the formation of these tissues. We hypothesized that the norma...

Adipose tissue is an attractive source of multipotent adult stem cells due to its wide-spread availability, accessibility, and ease of harvest. Adipose-derived stem cells (ASCs), the adherent stromal cell population present within adipose tissue, are easily expanded in culture, able to differentiate along multiple cell-lineage pathways, and have be...

Intravenous delivery of human adipose-derived stromal cells (hASCs) is a promising option for the treatment of ischemia. After delivery, hASCs that reside and persist in the injured extravascular space have been shown to aid recovery of tissue perfusion and function, although low rates of incorporation currently limit the safety and efficacy of the...

This review will cover the basic research performed with adipose stem cells (ASCs) over the past several years as well as pertinent translational research. The properties of ASCs that make them particularly interesting to the transplant surgeon will then be covered. These properties include regeneration of native tissue, support of microvasculature...

Detailed explanation of rule formulation and execution, model logic, and literature-based rules. (0.61 MB DOC)

Electrospinning has recently gained widespread attention as a process capable of producing nanoscale fibres that mimic native extracellular matrix. In this study, we compared the osteogenic differentiation behaviour of human adipose stem cells (ASCs) on a 3D nanofibre matrix of type I rat tail collagen (RTC) and a 2D RTC collagen-coated substrate,...

Microvascular changes of sludging and stasis are indications of thermal injury in tissue. This study investigates whether microvascular thermal injury can be decreased via topical application of poloxamer-188. Rat mesenteric microvessels were thermally injured and topically suffused with either Ringer's solution (control) or 5% poloxamer-188 in Rin...

A growing body of literature suggests that human adipose-derived stromal cells (hASCs) possess developmental plasticity both in vitro and in vivo, and might represent a viable cell source for therapeutic angiogenesis and tissue engineering. We investigate their phenotypic similarity to perivascular cell types, ability to contribute to in vivo micro...

Human adipose-derived stromal cells (hASCs) were evaluated in vitro for their ability to bind vascular adhesion and extracellular matrix proteins to arrest (firmly adhere) under physiological flow conditions. hASCs were flowed through a parallel plate flow chamber containing substrates presenting immobilized type I collagen, fibronectin, E-selectin...

The rodent bipedicle flap has been used in numerous permutations as a model of ischemia and to generate a compromised tissue bed. In this study 24 rats were used to investigate skin perfusion over time along the length of 4 distinct bipedicle flap designs-2 oriented cranial-caudally and 2 transverse. Traditional rectangular flaps were evaluated as...

The emerging field of regenerative medicine will require a reliable source of stem cells in addition to biomaterial scaffolds and cytokine growth factors. Adipose tissue represents an abundant and accessible source of adult stem cells with the ability to differentiate along multiple lineage pathways. The isolation, characterization, and preclinical...

Adipose tissue provides an easily accessible and abundant source of putative stem cells for translational clinical research. Currently prevalent culture techniques include the use of FBS, a highly variable and undefined component, which brings with it the potential for adverse patient reactions. In an effort to eliminate the use of animal products...

Adipose tissue provides an important extragonadal source of estrogen. Obesity-associated elevation of estrogen production increases risk of breast cancer in postmenopausal women. Aromatase (CYP19), which converts androgen to estrogen, is a key enzyme in estrogen biosynthesis. In normal adipose tissue, transcription of the aromatase gene is initiate...

As the promise of stem cell-based therapies begins to be realised, and efforts to bring advances to the clinic mount, the source of these cells is increasingly important. The morbidity associated with harvesting stem cells from solid organs and the invasive nature of bone marrow biopsies may limit their practicality for wider clinical applications....

Adipose tissue contains many cells and proteins that are of value not only because of their possible therapeutic applications but also because of the low cost of harvest and delivery. Plastic surgeons, with an operative domain that covers almost every major fat depot, have a unique opportunity and a vested interest in expanding basic and clinical r...

A variety of cell types are currently under investigation for their potential to regenerate tissues in vivo. A major challenge exists relating to the serial, non-invasive assessment of such cells after their implantation in vivo. An ideal assessment method would not only track cells over time in a non-invasive manner, but would also have the abilit...

Mutations in BRCA1 increase risks of familial breast and ovarian cancers, particularly among premenopausal women. While BRCA1 plays an active role in DNA repair, this function alone may not be sufficient to explain why BRCA1-associated tumors predominantly occur in estrogen-responsive tissues. Aromatase is the rate-limiting enzyme in estrogen biosy...

Little is known regarding the biology of fat considering its extensive use clinically in soft tissue implantation. Free-fat transfer is problematic the result of graft site volume loss, appearing histologically as the replacement of mature adipocytes with a fibroblast-like infiltrate. We hypothesize that these histologic changes reflect a dediffere...

Adult human subcutaneous adipose tissue contains cells with intriguing multilineage developmental plasticity, much like marrow-derived mesenchymal stem cells. Putative stem or progenitor cells from fat have been given many different names in the literature, reflecting an early and evolving consensus regarding their phenotypic characterization. The...

Background Surgical experience and anecdotal data on the most effective method of harvesting, preparing, and injecting autologous fat grafts are inconsistent and conflicting. Because the limitation of fat grafting is its resorption, understanding how various handling techniques affect adipocyte survival is crucial to optimizing its long-term surviv...

Surgical experience and anecdotal data on the most effective method of harvesting, preparing, and injecting autologous fat grafts are inconsistent and conflicting. Because the limitation of fat grafting is its resorption, understanding how various handling techniques affect adipocyte survival is crucial to optimizing its long-term survival. We soug...

Human subcutaneous fat-derived stem cells were recently shown to have the potential to differentiate in vitro into a variety of cell types, including adipocytes, osteoblasts, chondrocytes, and myoblasts (Zuk et al., Tissue Eng. 2001;7:211-228). Subcutaneous adipose tissue may therefore prove to be an easily acquired and abundant source of stem cell...

Learning objectives: The reader is presumed to have a broad understanding of plastic surgical procedures and concepts. After studying this article, the participant should be able to: Physicians may earn 1 hour of Category 1 CME credit by successfully completing the examination based on material covered in this article. The examination begins on pa...

Future cell-based therapies such as tissue engineering will benefit from a source of autologous pluripotent stem cells. For mesodermal tissue engineering, one such source of cells is the bone marrow stroma. The bone marrow compartment contains several cell populations, including mesenchymal stem cells (MSCs) that are capable of differentiating into...

In short, our device allows a surgeon who is harvesting adipose tissue for autologous fat transplantation to immediately, easily, efficiently, and sterilely isolate adipose tissue from the unwanted waste components that are associated with primary liposuction effluent. It does so by "trapping" the fat tissue contained within raw liposuction effluen...

Current efforts at autologous fat transfer involve the “mass” transplantation of intact tissue pieces. Such techniques are characterized by unpredictable results. New tissue engineering strategies are now emerging that propose to re-generate tissue via the ex vivo and in vivo manipulation of individual cells on a molecular level. This article revie...

The eventual development of tissue-engineered fat equivalents for reconstructive and augmentation purposes will be most welcome by nearly every surgical discipline and prove to be especially useful for plastic surgeons. The clinical applications for which tissue-engineered fat will be particularly useful are vast and varied and can be loosely categ...