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1.
JGH Open ; 7(11): 800-802, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38034052

ABSTRACT

A 47-year-old man with a background history of gastroesophageal reflux disease (GERD) and seasonal asthma underwent a gastroscopy for further investigation. Endoscopy revealed numerous polypoid lesions diffusely distributed in the lower third of the esophagus, with histology revealing squamous papilloma with occasional intraepithelial lymphocytes. The diagnosis was esophageal squamous papillomatosis (ESP), which is a rare condition characterized by exophytic and circumferential projections with friable mucosa diffusely spread through the esophagus with unclear etiology and malignancy risk.

2.
Plast Reconstr Surg Glob Open ; 11(6): e5100, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37388427

ABSTRACT

For over 100 years, autologous skin grafts have remained the gold standard for the reconstruction of wounds but are limited in availability. Acellular tissue-engineered skin constructs (acellular TCs) and cellular tissue-engineered skin constructs (cellular TCs) may address these limitations. This systematic review and meta-analysis compare outcomes between them. Methods: A systematic review was conducted using PRISMA guidelines, querying MEDLINE, Embase, Web of Science, and Cochrane to assess graft incorporation, failure, and wound healing. Case reports/series, reviews, in vitro/in vivo work, non-English articles or articles without full text were excluded. Results: Sixty-six articles encompassing 4076 patients were included. No significant differences were found between graft failure rates (P = 0.07) and mean difference of percent reepithelialization (p = 0.92) when split-thickness skin grafts were applied alone versus co-grafted with acellular TCs. Similar mean Vancouver Scar Scale was found for these two groups (p = 0.09). Twenty-one studies used at least one cellular TC. Weighted averages from pooled results did not reveal statistically significant differences in mean reepithelialization or failure rates for epidermal cellular TCs compared with split-thickness skin grafts (p = 0.55). Conclusions: This systematic review is the first to illustrate comparable functional and wound healing outcomes between split-thickness skin grafts alone and those co-grafted with acellular TCs. The use of cellular TCs seems promising from preliminary findings. However, these results are limited in clinical applicability due to the heterogeneity of study data, and further level 1 evidence is required to determine the safety and efficacy of these constructs.

3.
Physiol Rep ; 10(15): e15411, 2022 08.
Article in English | MEDLINE | ID: mdl-35924300

ABSTRACT

Prolonged tourniquet use can lead to tissue ischemia and can cause progressive muscle and nerve injuries. Such injuries are accompanied by calpain activation and subsequent Wallerian-like degeneration. Several known inhibitors, including leupeptin, are known to impede the activity of calpain and associated tissue damage. We hypothesize that employment of leupeptin in a rat model of prolonged hind limb ischemia can mitigate muscle and nerve injuries. Sprague-Dawley rats (n = 10) weighing between 300-400 g were employed in this study. Their left hind limbs were subjected to blood flow occlusion for a period of 2-h using a neonatal blood pressure cuff. Five rats were given twice weekly intramuscular leupeptin injections, while the other five received saline. After 2 weeks, the animals were euthanized, their sciatic nerves and gastrocnemius muscles were harvested, fixed, stained, and analyzed using NIH Image J software. The administration of leupeptin resulted in larger gastrocnemius muscle fiber cross-sectional areas for the right (non-tourniquet applied) hindlimb as compared to that treated with the saline (p = 0.0110). However, no statistically significant differences were found between these two groups for the injured left hindlimb (p = 0.1440). With regards to the sciatic nerve cross-sectional areas and sciatic functional index, no differences were detected between the leupeptin and control treated groups for both the healthy and injured hindlimbs. This research provides new insights on how to employ leupeptin to inhibit the degenerative effects of calpain and preserve tissues following ischemia resulting from orthopedic or plastic surgery procedures.


Subject(s)
Calpain , Ischemia , Animals , Hindlimb/blood supply , Ischemia/drug therapy , Leupeptins/pharmacology , Muscle, Skeletal , Rats , Rats, Sprague-Dawley
4.
Plast Reconstr Surg ; 150(3): 655e-670e, 2022 09 01.
Article in English | MEDLINE | ID: mdl-35791292

ABSTRACT

BACKGROUND: Negative-pressure wound therapy offers many advantages over standard surgical dressings in the treatment of open wounds, including accelerated wound healing, cost savings, and reduced complication rates. Although contraindicated by device manufacturers in malignancy-resected wounds because of hypothesized risk of tumor recurrence, negative-pressure wound therapy is still applied postoperatively because of limited clinical support. The authors performed a systematic review with meta-analysis to compare negative-pressure wound therapy outcomes with those of standard surgical dressings on open wounds, with their null hypothesis stating there would be no outcome differences. METHODS: A systematic review of the literature on negative-pressure wound therapy and standard surgical dressings on malignancy-resected wounds was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using PubMed, Embase, CINAHL, and Cochrane Central databases. Meta-analysis compared group outcomes, including malignancy recurrence, wound complication, and surgical site infection rates, with a random effects model. RESULTS: A total of 1634 studies were identified and 27 met eligibility criteria, including four randomized controlled trials, four prospective cohort studies, and 19 retrospective reviews. Eighty-one percent of articles ( n = 22) recommended negative-pressure wound therapy in malignancy-resected wounds. Meta-analysis determined that the treatment yielded significantly lower overall surgical site infection ( p = 0.004) and wound complication ( p = 0.01) rates than standard surgical dressings; however, there were no statistically significant differences found for other outcomes between the two groups. CONCLUSIONS: This review demonstrates favorable outcomes of negative-pressure wound therapy over standard surgical dressings for malignancy-resected wounds without an increased risk of malignancy recurrence. However, because limited randomized controlled trials (detailing only incisional wounds for limited malignancies and anatomic regions) are available, additional high-power randomized controlled trials are recommended.


Subject(s)
Negative-Pressure Wound Therapy , Bandages , Humans , Prospective Studies , Retrospective Studies , Surgical Wound Infection/epidemiology , Surgical Wound Infection/etiology , Surgical Wound Infection/prevention & control
5.
Cureus ; 14(5): e24896, 2022 May.
Article in English | MEDLINE | ID: mdl-35698713

ABSTRACT

Background Intertrochanteric fractures are common injuries among the elderly population and those with osteoporosis. The study was conducted in order to evaluate the outcome of Proximal Femoral Nail Antirotation II (PFN-A2) in the treatment of these fractures in elderly patients. Methods Twenty-five elderly patients (range 60 to 73 years) with trochanteric fractures who were treated with PFN-A2 at Government Medical College Amritsar were included in this prospective observational study. These patients were followed up regularly until six months post-operatively. The functional and radiological evaluations were done at six, 12, 16, and 20 weeks. The functional outcome was evaluated using the Harris Hip Score (HHS). Results The mean age incidence for trochanteric fractures was 64 years. There were no cases of intra-operative and postoperative femoral fractures. The mean operating time was 85.6 minutes. Radiological union was seen in all of the 25 patients. The mean time for fracture union time in our study was 13.8 weeks. The average Harris Hip Score in our study was calculated at three months as 74.3 and at six months as 85.08. The p-value was highly significant (0.001) for this improved outcome. This study found PFN-A2 related secondary varus deformities in 8.0% of the patients (two patients). Only one patient (4%) developed surgical site infection (SSI). Conclusion PFN-A2 provides adequate functional results in terms of fixation and healing. This can be further enhanced by good pre-operative planning, correct technique of entry point, and meticulous placement of implant with a helical blade in both anteroposterior (AP), lateral view, and distal locking and non-acceptance of reduction in varus. A good reduction is required to achieve a good functional outcome. We conclude that the PFN-A2 has the benefit of closed reduction, short operative time, preservation of biology, less soft tissue damage, and early rehab.

6.
Exp Dermatol ; 31(4): 516-527, 2022 04.
Article in English | MEDLINE | ID: mdl-34727395

ABSTRACT

Tissue engineering has been successful in reproducing human skin equivalents while incorporating new approaches such as three-dimensional (3D) bioprinting. The latter method offers a plethora of advantages including increased production scale, ability to incorporate multiple cell types and printing on demand. However, the quality of printed skin equivalents compared to those developed manually has never been assessed. To leverage the benefits of this method, it is imperative that 3D-printed skin should be structurally and functionally similar to real human skin. Here, we developed four bilayered human skin epidermal-dermal equivalents: non-printed dermis and epidermis (NN), printed dermis and epidermis (PP), printed epidermis and non-printed dermis (PN), and non-printed epidermis and printed dermis (NP). The effects of printing induced shear stress [0.025 kPa (epidermis); 0.049 kPa (dermis)] were characterized both at the cellular and at the tissue level. At cellular level, no statistically significant differences in keratinocyte colony-forming efficiency (CFE) (p = 0.1641) were observed. In the case of fibroblasts, no significant differences in the cell alignment index (p < 0.1717) and their ability to contract collagen gel (p = 0.851) were detected. At the tissue levels, all the four skin equivalents were characterized using histological and immunohistochemical analysis with no significant differences found in either epidermal basal cell count, thickness of viable epidermis, and relative intensity of filaggrin and claudin-1. Our results demonstrated that 3D printing can achieve the same high-quality skin constructs as have been developed traditionally, thus opening new avenues for numerous high-throughput industrial and clinical applications.


Subject(s)
Bioprinting , Bioprinting/methods , Fibroblasts/metabolism , Humans , Keratinocytes/metabolism , Printing, Three-Dimensional , Skin/pathology , Tissue Engineering/methods
7.
Ann Plast Surg ; 87(5): 506-508, 2021 11 01.
Article in English | MEDLINE | ID: mdl-33625024

ABSTRACT

BACKGROUND: One of the most commonly discussed benefits of macromastia treatment surgery, bilateral reduction mammaplasty, is the potential for subsequent weight loss. There is limited research examining weight change after reduction mammaplasty and a definitive relationship remains to be established. Our study aims to investigate this relationship and to identify potential preoperative and operative factors associated with postoperative changes in weight. METHODS: A retrospective chart review was performed of all patients who underwent bilateral reduction mammaplasty for symptomatic macromastia at a single academic institution (Stony Brook University Hospital) between January 1, 2000, and January 1, 2016. Patients had 12 months or longer of follow-up to track resultant postoperative weight. RESULTS: Two hundred and fifty-six patients met our eligibility criteria. The patients were stratified into 2 groups based on preoperative body mass index (BMI). Group 1 consisted of 112 patients (44%) with a BMI less than 30 (ie, nonobese); group 2 consisted of 145 patients (56%) with a BMI of 30 or higher (ie, obese). The mean total weight of bilateral breast tissue resected for each group was 982 and 1719 g for groups 1 and 2, respectively. For both groups, the mean patient age was 38 years, and the mean follow-up period was approximately 5 years. Patients in group 1 (the nonobese group) had a mean preoperative BMI of 26.25 and postoperative BMI of 26.78 (P = 0.108). Postoperatively, these patients demonstrated an overall mean BMI increase of 0.90. Patients in group 2 (the obese group) had a mean preoperative BMI of 34.99 and postoperative BMI of 34.13 (P = 0.045). Postoperatively, they demonstrated an overall mean BMI decrease of 0.20. The difference in change of BMI between the 2 groups was determined to be significant (P = 0.047). There is a significantly larger mean decrease in BMI in the obese group, 3.86 than the nonobese group, 2.01 (P = 0.006). CONCLUSIONS: We found that weight changes after undergoing bilateral reduction mammaplasty are significantly different between obese and nonobese patients. Obese patients (BMI, ≥30) experience greater weight loss than nonobese patients. As the desire for postoperative weight loss and increased physical activity are common reasons to undergo reduction mammaplasty, this study adds valuable data to the discussion.


Subject(s)
Mammaplasty , Weight Loss , Adult , Body Mass Index , Breast/surgery , Female , Humans , Obesity/complications , Obesity/surgery , Retrospective Studies , Treatment Outcome
8.
Cyborg Bionic Syst ; 2021: 9816913, 2021.
Article in English | MEDLINE | ID: mdl-36285133

ABSTRACT

Intraoperative confirmation of negative resection margins is an essential component of soft tissue sarcoma surgery. Frozen section examination of samples from the resection bed after excision of sarcomas is the gold standard for intraoperative assessment of margin status. However, it takes time to complete histologic examination of these samples, and the technique does not provide real-time diagnosis in the operating room (OR), which delays completion of the operation. This paper presents a study and development of sensing technology using Raman spectroscopy that could be used for detection and classification of the tumor after resection with negative sarcoma margins in real time. We acquired Raman spectra from samples of sarcoma and surrounding benign muscle, fat, and dermis during surgery and developed (i) a quantitative method (QM) and (ii) a machine learning method (MLM) to assess the spectral patterns and determine if they could accurately identify these tissue types when compared to findings in adjacent H&E-stained frozen sections. High classification accuracy (>85%) was achieved with both methods, indicating that these four types of tissue can be identified using the analytical methodology. A hand-held Raman probe could be employed to further develop the methodology to obtain spectra in the OR to provide real-time in vivo capability for the assessment of sarcoma resection margin status.

9.
Ann Plast Surg ; 85(S1 Suppl 1): S127-S128, 2020 07.
Article in English | MEDLINE | ID: mdl-32205494

ABSTRACT

INTRODUCTION: Advanced levels of professorship and executive positions are considered markers of success in medical academia. Despite sex parity in medical school graduates, sex disparities within positions of power remain unequal. The purpose of this study was to analyze sex composition at different levels of leadership at multiple academic, highly ranked institutions. METHODS: Hospital executives and academic plastic surgery faculty were identified through an internet-based search of all Accreditation Council for Graduate Medical Education-accredited plastic surgery integrated and independent residency training programs. Institutions from the U.S. News 2018-19 Top 20 Best Hospitals Honor Roll and Beckers Review 2018: 100 Great Hospitals in America were also included. Information on board of directors/trustees (BOD), administrators, and plastic surgery faculty with focus on title, sex, degree, specialty, and academic rank was collected from departmental and hospital websites. Duplicate institutions were excluded. RESULTS: Data on chief executive officers (CEOs)/presidents (n = 275) and BOD members (n = 5347) from 153 medical institutions were analyzed. Physicians consisted of 40.7% (n = 112) of CEOs/presidents, of which 10.7% (n = 12) were surgeons, and 15.6% (n = 835) of the BOD membership. Female physicians in executive roles were disproportionally low, consisting of 5% (n = 14) of CEOs/presidents, reaching significance (P = 0.033).Sex representation within plastic surgery departments demonstrated similar trends. Women comprised 18.3% of the overall plastic surgery faculty (n = 1441). Significant differences between mean male and female plastic surgeons (8.2 vs 1.84, P = <0.001) were observed. In addition, female plastic surgeons represented only 26.3% of all assistant professors (P = <0.001), 18.75% of total associate professors (P = <0.001), and 7.8% of full professors (P = <0.001). CONCLUSIONS: Although women are increasingly pursuing careers in medicine and surgery, the data suggest that there remains a paucity of female physicians in top leadership roles. At the departmental level, female plastic surgeons are also underrepresented. At the executive level, men make up over 88% of physician CEOs at the highest-ranked medical institutions. This study further highlights the need for the development of educational, mentorship, and career pathways to further improve female representation in positions of power within academia.


Subject(s)
Physician Executives , Surgeons , Surgery, Plastic , Faculty, Medical , Female , Humans , Male , Schools, Medical , Surgery, Plastic/education , United States
10.
Ann Plast Surg ; 85(S1 Suppl 1): S41-S43, 2020 07.
Article in English | MEDLINE | ID: mdl-32205497

ABSTRACT

BACKGROUND: Fibrin sealant is a controversial method for reducing seroma formation. It is comprised of human proclotting factors, fibrinogen and thrombin. Fibrin sealants have been extensively studied for their efficacy in reducing the rates of seroma by sealing the dead space; however, in most studies, the sealants are used with surgical drains. According to the U.S. Food and Drug Administration, fibrin sealant carries the risk of life-threatening thromboembolic complications, gas emboli, and transmission of infectious agents. Despite these concerns, many plastic surgeons use such products in ambulatory surgeries even though its effect on seroma formation has yet to be elucidated. The aim of our study is to determine the efficacy of fibrin sealants in seroma prevention in reduction mammoplasty with and without surgical drains. METHODS: A retrospective chart review was performed of all bilateral reduction mammaplasty by a single-surgeon from 2014 to 2018. Patients had at least 90 days postoperative follow-up. Exclusion criteria consisted of patients younger than 18 years, had prior breast surgery, or had an incidental cancer diagnosis in breast reduction tissue specimen. RESULTS: On analysis, 159 patients met inclusion criteria and were categorized into group 1, with fibrin sealant (n = 101) and group 2, no fibrin sealant (n = 58). There were no statistical differences in patient demographics. There was no significant difference in the incidence of seroma between group 1 and group 2 (21% vs 19%, P = 0.782). Group 1 incidence of seroma was further analyzed by sealant type: Tisseal, Floseal, and Evicel (12% vs 27% vs 23%, P = 0.436). In group 1, the use of sealant alone was more likely to result in seroma formation when compared with the combination of sealant and surgical drains (25% vs 8%, P = 0.069). CONCLUSIONS: There is no difference in rate of seroma formation with the use of fibrin sealants in reduction mammaplasty. The use of fibrin sealants without surgical drains may increase the rate of seromas. Plastic surgeons could consider weighing the risk versus benefits in using fibrin sealants with or without drains in ambulatory surgeries.


Subject(s)
Mammaplasty , Surgeons , Female , Fibrin Tissue Adhesive/therapeutic use , Humans , Postoperative Complications/epidemiology , Postoperative Complications/prevention & control , Retrospective Studies , Seroma/epidemiology , Seroma/etiology , Seroma/prevention & control
11.
Plast Reconstr Surg Glob Open ; 7(8): e2355, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31592026

ABSTRACT

The use of acellular dermal matrices (ADMs) in breast reconstruction is a controversial topic. Recent literature has investigated the effects of ADM sterilization on infectious complications, although with varying conclusions. Previous work by our group showed no difference between aseptic and sterilized products immediately out of the package. In this study, we investigate the microbiologic profiles of these agents after implantation. METHODS: In this prospective study, we cultured samples of ADM previously implanted during the first stage of tissue expander-based immediate breast reconstruction. A 1 cm2 sample was excised during the stage II expander-implant exchange procedure, and samples were incubated for 48 hours in tryptic soy broth. Samples with growth were further cultured on tryptic soy broth and blood agar plates. Patient records were also analyzed, to determine if ADM sterilization and microbial growth were correlated with infectious complications. RESULTS: In total, 51 samples of ADM were collected from 32 patients. Six samples were from aseptic ADM (AlloDerm), 27 samples were from ADM sterilized to 10-3 (AlloDerm Ready-to-Use), and 18 samples were from products sterilized to 10-6 (AlloMax). No samples demonstrated bacterial growth. Only 5 patients experienced postoperative complications, of whom only 1 patient was infectious in nature. We failed to demonstrate a statistically significant correlation between sterility and postoperative complications. CONCLUSIONS: Our findings showed no difference in microbial presence and clinical outcomes when comparing ADM sterility. Furthermore, no samples demonstrated growth in culture. Our study brings into question the necessity for terminal sterilization in these products.

12.
Plast Reconstr Surg Glob Open ; 7(5): e2264, 2019 May.
Article in English | MEDLINE | ID: mdl-31333980

ABSTRACT

INTRODUCTION: The use of vascular grafts is continuing to rise due to the increasing prevalence of coronary artery bypass grafting and microvascular flap-based tissue reconstructions. The current options of using native vessels (saphenous vein) or the synthetic grafts (Dacron) have been unable to manage current needs. In this study, we employed an original tissue engineering approach to develop a multi-layered vascular graft that has the potential to address some of the limitations of the existing grafts. MATERIALS AND METHODS: Biomaterials, gelatin and fibrin, were used to develop a two-layered vascular graft. The graft was seeded with endothelial cells and imaged using confocal microscopy. The graft's architecture and its mechanical properties were also characterized using histology, Scanning Electron Microscopy and rheological studies. RESULTS: Our methodology resulted in the development of a vascular graft with precise spatial localization of the two layers. The endothelial cells fully covered the lumen of the developed vascular graft, thus providing a non-thrombogenic surface. The elastic modulus of the biomaterials employed in this graft was found to be 5.186 KPa, paralleling that of internal mammary artery. The burst pressure of this graft was also measured and was found close to that of the saphenous vein (~2000 mm Hg). CONCLUSIONS: We were successfully able to employ a unique method to synthesize a multi-layered vascularized graft having adequate biological and mechanical properties. Studies are ongoing involving implantation of this developed vascular graft in the rat femoral artery and characterization of parameters such as vascular remodeling and patency.

13.
Eur J Vasc Endovasc Surg ; 55(3): 417-424, 2018 03.
Article in English | MEDLINE | ID: mdl-29336975

ABSTRACT

BACKGROUND: The physical properties of a venous thrombus are derived from molecular characteristics, including fibrin polymer diameter, density, branching, and cross-linking. Dense thrombi with thin, highly branched fibrin fibres and small pores in the meshwork have been observed to be more rigid, less permeable, and more resistant to lysis. The three dimensional fibrin meshwork acts as the main structure to entrap and capture erythrocytes, platelets and plasma components. Attached factors become integrated into the developing thrombus, co-localise with fibrin deposition and act in either a pro- or anticoagulant capacity. Similarly, factors including blood flow, osmolarity and pH, oxidative stress, platelet and leukocyte recruitment, and thrombin concentration alter thrombus composition, architecture, and its mechanical properties. CONCLUSIONS: Over time, an increase in thrombus cellular composition and a linear decrease in fibrin content as a function of thrombus age is observed. However, little else is known regarding the evolution of fibrin based clots. The role of fibrin in mediating cellular coordination, thrombus maturation, and changes of the venous wall also requires further research. This review discusses the current impact of fibrin on thrombus remodeling and addresses the limitations of the work done in this area.


Subject(s)
Blood Coagulation , Fibrin/metabolism , Veins/metabolism , Venous Thrombosis/blood , Animals , Elasticity , Fibrin/chemistry , Fibrinolysis , Humans , Protein Conformation , Structure-Activity Relationship , Time Factors , Vascular Remodeling , Veins/pathology , Venous Thrombosis/pathology , Viscosity
14.
Mo Med ; 114(4): 311-315, 2017.
Article in English | MEDLINE | ID: mdl-30228618

ABSTRACT

Neurocognitive and sleep problems are common, underdiagnosed, and frequently co-morbid. Sleep disruption, and fatigue, predict cognitive impairment. Cognitive impairment, in turn, can worsen sleep hygiene. In dementia patients, sleep disorders are common, and dementia medications affect sleep. Emerging insights on the brain's glymphatic system suggests that sleep may drive clearance of Aß peptide to affect Alzheimer pathophysiology. Parkinsonian dementias are linked with REM behavior disorder, a highly treatable problem that predicts future conversion into dementia.


Subject(s)
Cognitive Dysfunction/diagnosis , Dementia/diagnosis , Sleep Wake Disorders/complications , Amyloid beta-Peptides/metabolism , Cognitive Dysfunction/complications , Cognitive Dysfunction/epidemiology , Dementia/etiology , Dementia/physiopathology , Humans , Neuropsychological Tests/standards , Parkinsonian Disorders/etiology , Peptide Fragments/metabolism , REM Sleep Behavior Disorder/complications , REM Sleep Behavior Disorder/physiopathology , Sleep Wake Disorders/diagnosis , Sleep Wake Disorders/epidemiology
15.
Int J Surg Case Rep ; 15: 30-1, 2015.
Article in English | MEDLINE | ID: mdl-26301682

ABSTRACT

INTRODUCTION: Umbilical and paraumblical abscess can occur in children with presenting complaint of discharge from umbilical region. However, patent vitello intestinal duct presenting as paraumblical abscess is rare phenomenon. PRESENTATION OF CASE: One year old male child presented with complain of discharge from umbilical region since birth. Incision & drainage done twice thinking it to be paraumblical abscess. DISCUSSION: Vitellointestinal duct as abscess is rare presentation but it should be considered as a differential diagnosis of discharging umbilicus as management of abscess and patent duct are different. CONCLUSION: Patent vitellointestinal duct can present as paraumbilical abscess, and it should be kept in differential diagnosis specifically in children.

16.
J Nanotechnol Eng Med ; 5(4): 0409051-4090511, 2014 Nov.
Article in English | MEDLINE | ID: mdl-26336575

ABSTRACT

The following work describes the development of a novel noninvasive transmucosal drug delivery system, the chitosan sponge matrix (CSM). It is composed of cationic chitosan (CS) nanoparticles (NPs) that encapsulate cisplatin (CDDP) embedded within a polymeric mucoadhesive CS matrix. CSM is designed to swell up when exposed to moisture, facilitating release of the NPs via diffusion across the matrix. CSM is intended to be administered topically and locally to mucosal tissues, with its initial indication being oral cancer (OC). Currently, intravenous (IV) administered CDDP is the gold standard chemotherapeutic agent used in the treatment of OC. However, its clinical use has been limited by its renal and hemotoxicity profile. We aim to locally administer CDDP via encapsulation in CS NPs and deliver them directly to the oral cavity with CSM. It is hypothesized that such a delivery device will greatly reduce any systemic toxicity and increase antitumor efficacy. This paper describes the methods for developing CSM and maintaining the integrity of CDDP NPs embedded in the CSM.

17.
Tissue Eng Part C Methods ; 20(6): 473-84, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24188635

ABSTRACT

Three-dimensional (3D) bioprinting, a flexible automated on-demand platform for the free-form fabrication of complex living architectures, is a novel approach for the design and engineering of human organs and tissues. Here, we demonstrate the potential of 3D bioprinting for tissue engineering using human skin as a prototypical example. Keratinocytes and fibroblasts were used as constituent cells to represent the epidermis and dermis, and collagen was used to represent the dermal matrix of the skin. Preliminary studies were conducted to optimize printing parameters for maximum cell viability as well as for the optimization of cell densities in the epidermis and dermis to mimic physiologically relevant attributes of human skin. Printed 3D constructs were cultured in submerged media conditions followed by exposure of the epidermal layer to the air-liquid interface to promote maturation and stratification. Histology and immunofluorescence characterization demonstrated that 3D printed skin tissue was morphologically and biologically representative of in vivo human skin tissue. In comparison with traditional methods for skin engineering, 3D bioprinting offers several advantages in terms of shape- and form retention, flexibility, reproducibility, and high culture throughput. It has a broad range of applications in transdermal and topical formulation discovery, dermal toxicity studies, and in designing autologous grafts for wound healing. The proof-of-concept studies presented here can be further extended for enhancing the complexity of the skin model via the incorporation of secondary and adnexal structures or the inclusion of diseased cells to serve as a model for studying the pathophysiology of skin diseases.


Subject(s)
Fibroblasts/cytology , Keratinocytes/cytology , Printing, Three-Dimensional , Skin, Artificial , Skin/cytology , Skin/growth & development , Tissue Engineering/instrumentation , Bioprosthesis , Cell Proliferation/physiology , Cell Survival/physiology , Cells, Cultured , Coculture Techniques/instrumentation , Coculture Techniques/methods , Fibroblasts/physiology , Humans , Keratinocytes/physiology , Organ Culture Techniques/instrumentation , Organ Culture Techniques/methods , Tissue Engineering/methods
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