1
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Tsai KHY, Shi H, Parungao RJ, Naficy S, Ding X, Ding X, Hew JJ, Wang X, Chrzanowski W, Lavery GG, Li Z, Issler-Fisher AC, Chen J, Tan Q, Maitz PK, Cooper MS, Wang Y. Skin 11β-hydroxysteroid dehydrogenase type 1 enzyme expression regulates burn wound healing and can be targeted to modify scar characteristics. Burns Trauma 2023; 11:tkac052. [PMID: 36694861 PMCID: PMC9862341 DOI: 10.1093/burnst/tkac052] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/29/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
BACKGROUND Excessive scarring and fibrosis are the most severe and common complications of burn injury. Prolonged exposure to high levels of glucocorticoids detrimentally impacts on skin, leading to skin thinning and impaired wound healing. Skin can generate active glucocorticoids locally through expression and activity of the 11β-hydroxysteroid dehydrogenase type 1 enzyme (11β-HSD1). We hypothesised that burn injury would induce 11β-HSD1 expression and local glucocorticoid metabolism, which would have important impacts on wound healing, fibrosis and scarring. We additionally proposed that pharmacological manipulation of this system could improve aspects of post-burn scarring. METHODS Skin 11β-HSD1 expression in burns patients and mice was examined. The impacts of 11β-HSD1 mediating glucocorticoid metabolism on burn wound healing, scar formation and scar elasticity and quality were additionally examined using a murine 11β-HSD1 genetic knockout model. Slow-release scaffolds containing therapeutic agents, including active and inactive glucocorticoids, were developed and pre-clinically tested in mice with burn injury. RESULTS We demonstrate that 11β-HSD1 expression levels increased substantially in both human and mouse skin after burn injury. 11β-HSD1 knockout mice experienced faster wound healing than wild type mice but the healed wounds manifested significantly more collagen deposition, tensile strength and stiffness, features characteristic of excessive scarring. Application of slow-release prednisone, an inactive glucocorticoid, slowed the initial rate of wound closure but significantly reduced post-burn scarring via reductions in inflammation, myofibroblast generation, collagen production and scar stiffness. CONCLUSIONS Skin 11β-HSD1 expression is a key regulator of wound healing and scarring after burn injury. Application of an inactive glucocorticoid capable of activation by local 11β-HSD1 in skin slows the initial rate of wound closure but significantlyimproves scar characteristics post burn injury.
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Affiliation(s)
- Kevin H-Y Tsai
- Adrenal Steroid Group, ANZAC Research Institute, Concord Hospital, The University of Sydney, Sydney, NSW 2137, Australia
- Burns and Reconstructive Surgery Research Group, ANZAC Research Institute, Concord Hospital, The University of Sydney, Sydney, NSW 2137, Australia
| | - Huaikai Shi
- Burns and Reconstructive Surgery Research Group, ANZAC Research Institute, Concord Hospital, The University of Sydney, Sydney, NSW 2137, Australia
| | - Roxanne J Parungao
- Burns and Reconstructive Surgery Research Group, ANZAC Research Institute, Concord Hospital, The University of Sydney, Sydney, NSW 2137, Australia
| | - Sina Naficy
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia
| | - Xiaotong Ding
- Jiangsu Provincial Engineering Research Centre of TCM External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China
| | - Xiaofeng Ding
- Department of Burns and Plastic Surgery, Nanjing Drum Tower Hospital Clinical College, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210008, China
| | - Jonathan J Hew
- Burns and Reconstructive Surgery Research Group, ANZAC Research Institute, Concord Hospital, The University of Sydney, Sydney, NSW 2137, Australia
| | - Xiaosuo Wang
- Heart Research Institute, The University of Sydney, Sydney, NSW 2006 , Australia
| | - Wojciech Chrzanowski
- Sydney Nano Institute, Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
| | - Gareth G Lavery
- Department of Biosciences, Centre for Healthy Ageing and Understanding Disease, Nottingham Trent University, NG1 4BU, UK
| | - Zhe Li
- Burns and Reconstructive Surgery Unit, Concord Repatriation General Hospital, Sydney, NSW 2137, Australia
| | - Andrea C Issler-Fisher
- Burns and Reconstructive Surgery Unit, Concord Repatriation General Hospital, Sydney, NSW 2137, Australia
| | - Jun Chen
- Jiangsu Provincial Engineering Research Centre of TCM External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, China
| | - Qian Tan
- Department of Burns and Plastic Surgery, Nanjing Drum Tower Hospital Clinical College, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210008, China
| | - Peter K Maitz
- Burns and Reconstructive Surgery Research Group, ANZAC Research Institute, Concord Hospital, The University of Sydney, Sydney, NSW 2137, Australia
- Burns and Reconstructive Surgery Unit, Concord Repatriation General Hospital, Sydney, NSW 2137, Australia
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Ding X, Tang Q, Xu Z, Xu Y, Zhang H, Zheng D, Wang S, Tan Q, Maitz J, Maitz PK, Yin S, Wang Y, Chen J. Challenges and innovations in treating chronic and acute wound infections: from basic science to clinical practice. Burns Trauma 2022; 10:tkac014. [PMID: 35611318 PMCID: PMC9123597 DOI: 10.1093/burnst/tkac014] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/06/2022] [Indexed: 12/30/2022]
Abstract
Acute and chronic wound infection has become a major worldwide healthcare burden leading to significantly high morbidity and mortality. The underlying mechanism of infections has been widely investigated by scientist, while standard wound management is routinely been used in general practice. However, strategies for the diagnosis and treatment of wound infections remain a great challenge due to the occurrence of biofilm colonization, delayed healing and drug resistance. In the present review, we summarize the common microorganisms found in acute and chronic wound infections and discuss the challenges from the aspects of clinical diagnosis, non-surgical methods and surgical methods. Moreover, we highlight emerging innovations in the development of antimicrobial peptides, phages, controlled drug delivery, wound dressing materials and herbal medicine, and find that sensitive diagnostics, combined treatment and skin microbiome regulation could be future directions in the treatment of wound infection.
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Affiliation(s)
- Xiaotong Ding
- School of Pharmacy, Jiangsu Provincial Engineering Research Center of Traditional Chinese Medicine External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing 210023, People's Republic of China
| | - Qinghan Tang
- School of Pharmacy, Jiangsu Provincial Engineering Research Center of Traditional Chinese Medicine External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing 210023, People's Republic of China
| | - Zeyu Xu
- School of Pharmacy, Jiangsu Provincial Engineering Research Center of Traditional Chinese Medicine External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing 210023, People's Republic of China
| | - Ye Xu
- Department of Burns and Plastic Surgery, The affiliated Drum Tow Hospital of Nanjing University of Chinese Medicine, Nanjing 210008, People's Republic of China
| | - Hao Zhang
- Department of Burns and Plastic Surgery, The affiliated Drum Tow Hospital of Nanjing University of Chinese Medicine, Nanjing 210008, People's Republic of China
| | - Dongfeng Zheng
- Department of Burns and Plastic Surgery, The affiliated Drum Tow Hospital of Nanjing University of Chinese Medicine, Nanjing 210008, People's Republic of China
| | - Shuqin Wang
- Department of Burns and Plastic Surgery, The affiliated Drum Tow Hospital of Nanjing University of Chinese Medicine, Nanjing 210008, People's Republic of China
| | - Qian Tan
- Department of Burns and Plastic Surgery, The affiliated Drum Tow Hospital of Nanjing University of Chinese Medicine, Nanjing 210008, People's Republic of China
| | - Joanneke Maitz
- Burns Injury and Reconstructive Surgery Research, ANZAC Research Institute, University of Sydney, Sydney, Australia, 2137
| | - Peter K Maitz
- Burns Injury and Reconstructive Surgery Research, ANZAC Research Institute, University of Sydney, Sydney, Australia, 2137
| | - Shaoping Yin
- School of Pharmacy, Jiangsu Provincial Engineering Research Center of Traditional Chinese Medicine External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing 210023, People's Republic of China
| | - Yiwei Wang
- School of Pharmacy, Jiangsu Provincial Engineering Research Center of Traditional Chinese Medicine External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing 210023, People's Republic of China
| | - Jun Chen
- School of Pharmacy, Jiangsu Provincial Engineering Research Center of Traditional Chinese Medicine External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing 210023, People's Republic of China
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3
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Shi H, Tsai KHY, Ma D, Wang X, Desai R, Parungao RJ, Hunt NJ, Cheng YY, Zhang H, Xu Y, Simanainen U, Tan Q, Cooper MS, Handelsman DJ, Maitz PK, Wang Y. Controlled dual release of dihydrotestosterone and flutamide from polycaprolactone electrospun scaffolds accelerate burn wound healing. FASEB J 2022; 36:e22310. [PMID: 35394674 PMCID: PMC9540550 DOI: 10.1096/fj.202101803r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/04/2022] [Accepted: 03/29/2022] [Indexed: 11/23/2022]
Abstract
Wound healing is a complex process involving multiple independent and overlapping sequential physiological mechanisms. In addition to cutaneous injury, a severe burn stimulates physiological derangements that induce a systemic hypermetabolic response resulting in impaired wound healing. Topical application of the anti‐androgen drug, flutamide accelerates cutaneous wound healing, whereas paradoxically systemic dihydrotestosterone (DHT) improves burn wound healing. We developed and characterized a PCL scaffold that is capable of controlled release of androgen (DHT) and anti‐androgen (F) individually or together. This study aims to investigate whether local modification of androgen actions has an impact on burn injury wound healing. In a full‐thickness burn wound healing, mouse model, DHT/F‐scaffold showed a significantly faster wound healing compared with F‐scaffold or DHT‐scaffold. Histology analysis confirmed that DHT/F‐scaffold exhibited higher re‐epithelization, cell proliferation, angiogenesis, and collagen deposition. Dual release of DHT and F from PCL scaffolds promoted cell proliferation of human keratinocytes and alters the keratinocyte cell cycle. Lastly, no adverse effects on androgen‐dependent organs, spleen and liver were observed. In conclusion, we demonstrated DHT plus F load PCL scaffolds accelerated burn wound healing when loading alone did not. These findings point to a complex role of androgens in burn wound healing and open novel therapeutic avenues for treating severe burn patients.
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Affiliation(s)
- Huaikai Shi
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia.,Asbestos Disease Research Institute, Concord Hospital, Sydney, Australia
| | - Kevin H-Y Tsai
- Adrenal Steroids Laboratory, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia
| | - Duncan Ma
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia
| | - Xiaosuo Wang
- Bosch Mass Spectrometry Facility, University of Sydney, Sydney, Australia
| | - Reena Desai
- Department of Andrology, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia
| | - Roxanne J Parungao
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia
| | - Nicholas J Hunt
- Biogerontology Group, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia.,Sydney Nano Institute, University of Sydney, Sydney, Australia.,Charles Perkins Centre, University of Sydney, Sydney, Australia
| | - Yuen Yee Cheng
- Asbestos Disease Research Institute, Concord Hospital, Sydney, Australia
| | - Hao Zhang
- Department of Burns and Plastic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Ye Xu
- Department of Burns and Plastic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Ulla Simanainen
- Department of Andrology, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia
| | - Qian Tan
- Department of Burns and Plastic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, China
| | - Mark S Cooper
- Adrenal Steroids Laboratory, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia
| | - David J Handelsman
- Department of Andrology, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia
| | - Peter K Maitz
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia.,Burns Unit, Concord Repatriation General Hospital, Concord, Australia
| | - Yiwei Wang
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia.,Jiangsu Provincial Engineering Research Centre of TCM External Medication Development and Application, Nanjing University of Chinese Medicine, Nanjing, China
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4
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Hew JJ, Parungao RJ, Mooney CP, Smyth JK, Kim S, Tsai KHY, Shi H, Chong C, Chan RCF, Attia B, Nicholls C, Li Z, Solon-Biet SM, Le Couteur DG, Simpson SJ, Jeschke MG, Maitz PK, Wang Y. Low-protein diet accelerates wound healing in mice post-acute injury. Burns Trauma 2021; 9:tkab010. [PMID: 34377708 PMCID: PMC8350350 DOI: 10.1093/burnst/tkab010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 12/06/2020] [Accepted: 03/11/2021] [Indexed: 11/13/2022]
Abstract
BACKGROUND Wound healing processes are influenced by macronutrient intake (protein, carbohydrate and fat). The most favourable diet for cutaneous wound healing is not known, although high-protein diets are currently favoured clinically. This experimental study investigates the optimal macronutrient balance for cutaneous wound healing using a mouse model and the Geometric Framework, a nutrient modelling method, capable of analyzing the individual and interactive effects of a wide spectrum of macronutrient intake. METHODS Two adjacent and identical full-thickness skin excisions (1 cm2) were surgically created on the dorsal area of male C57BL/6 mice. Mice were then allocated to one of 12 high-energy diets that varied in protein, carbohydrate and fat content. In select diets, wound healing processes, cytokine expression, energy expenditure, body composition, muscle and fat reserves were assessed. RESULTS Using the Geometric Framework, we show that a low-protein intake, coupled with a balanced intake of carbohydrate and fat is optimal for wound healing. Mice fed a low-protein diet progressed quickly through wound healing stages with favourable wound inflammatory cytokine expression and significantly accelerated collagen production. These local processes were associated with an increased early systemic inflammatory response and a higher overall energy expenditure, related to metabolic changes occurring in key macronutrient reserves in lean body mass and fat depots. CONCLUSIONS The results suggest that a low-protein diet may have a greater potential to accelerate wound healing than the current clinically used high-protein diets.
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Affiliation(s)
- Jonathan J Hew
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Roxanne J Parungao
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Craig P Mooney
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Julian K Smyth
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Sarah Kim
- Bone Biology Group, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Kevin H-Y Tsai
- Adrenal Steroids Laboratory, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Huaikai Shi
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Cassandra Chong
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Renee C F Chan
- Electron Microscopy Unit, Anatomical Pathology, Concord Hospital, Sydney, Australia 2139
| | - Beba Attia
- Electron Microscopy Unit, Anatomical Pathology, Concord Hospital, Sydney, Australia 2139
| | - Caroline Nicholls
- Burns Unit, Concord Repatriation General Hospital, Concord, Australia 2139
| | - Zhe Li
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
- Burns Unit, Concord Repatriation General Hospital, Concord, Australia 2139
| | - Samantha M Solon-Biet
- Ageing and Alzheimer Institute and ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
- Charles Perkins Centre and School of Life and Environmental Sciences, University of Sydney, Australia 2006
| | - David G Le Couteur
- Ageing and Alzheimer Institute and ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
| | - Stephen J Simpson
- Charles Perkins Centre and School of Life and Environmental Sciences, University of Sydney, Australia 2006
| | - Marc G Jeschke
- Sunnybrook Research Institute, Toronto, Ontario, Canada, M4N 3M5
| | - Peter K Maitz
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
- Burns Unit, Concord Repatriation General Hospital, Concord, Australia 2139
| | - Yiwei Wang
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia 2139
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, PR China 210023
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5
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Shi H, Cheer K, Simanainen U, Lesmana B, Ma D, Hew JJ, Parungao RJ, Li Z, Cooper MS, Handelsman DJ, Maitz PK, Wang Y. The contradictory role of androgens in cutaneous and major burn wound healing. Burns Trauma 2021; 9:tkaa046. [PMID: 33928173 PMCID: PMC8058007 DOI: 10.1093/burnst/tkaa046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/31/2020] [Indexed: 01/25/2023]
Abstract
Wound healing is a complex process involving four overlapping phases: haemostasis, inflammation, cell recruitment and matrix remodeling. In mouse models, surgical, pharmacological and genetic approaches targeting androgen actions in skin have shown that androgens increase interleukin-6 and tumor necrosis factor-α production and reduce wound re-epithelization and matrix deposition, retarding cutaneous wound healing. Similarly, clinical studies have shown that cutaneous wound healing is slower in men compared to women. However, in major burn injury, which triggers not only local wound-healing processes but also systemic hypermetabolism, the role of androgens is poorly understood. Recent studies have claimed that a synthetic androgen, oxandrolone, increases protein synthesis, improves lean body mass and shortens length of hospital stay. However, the possible mechanisms by which oxandrolone regulates major burn injury have not been reported. In this review, we summarize the current findings on the roles of androgens in cutaneous and major burn wound healing, as well as androgens as a potential therapeutic treatment option for patients with major burn injuries.
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Affiliation(s)
- Huaikai Shi
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Kenny Cheer
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Ulla Simanainen
- Andrology, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Brian Lesmana
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Duncan Ma
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Jonathan J Hew
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Roxanne J Parungao
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Zhe Li
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia.,Burns and Reconstructive Surgery Unit, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Mark S Cooper
- Adrenal Steroid Laboratory, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - David J Handelsman
- Andrology, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Peter K Maitz
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia.,Burns and Reconstructive Surgery Unit, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
| | - Yiwei Wang
- Burns Research Group, ANZAC Research Institute, University of Sydney, Concord Hospital, Gate, 3 Hospital road, Concord, NSW 2139, Australia
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6
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Shi H, Lo TH, Ma D, Condor B, Lesmana B, Parungao RJ, Tsai KHY, Kim S, Chen HT, Silveira PA, Li Z, Cooper MS, Simanainen U, Handelsman DJ, Maitz PK, Wang Y. Dihydrotestosterone (DHT) Enhances Wound Healing of Major Burn Injury by Accelerating Resolution of Inflammation in Mice. Int J Mol Sci 2020; 21:ijms21176231. [PMID: 32872240 PMCID: PMC7504698 DOI: 10.3390/ijms21176231] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/17/2020] [Accepted: 08/21/2020] [Indexed: 12/30/2022] Open
Abstract
Androgens have been known to inhibit cutaneous wound healing in men and male mice. However, in children with major burn injuries, a synthetic androgen was reported clinically to improve wound healing. The aim of this study is to investigate the role of dihydrotestosterone (DHT) as a new therapeutic approach in treating major burn injury. In the present study, mice received systemic androgen treatment post major burn injury. Wound healing rate and body weight were monitored over 21 days. The serum level of inflammatory cytokines/chemokines were measured using multiplex immunoassays. In addition, splenocyte enumeration was performed by flow cytometry. Healing phases of inflammation, re-epithelialization, cell proliferation and collagen deposition were also examined. In results, DHT treated mice lost less weight and displayed accelerated wound healing but has no impact on hypermetabolism. Mice, after burn injury, displayed acute systemic inflammatory responses over 21 days. DHT treatment shortened the systemic inflammatory response with reduced splenic weight and monocyte numbers on day 14 and 21. DHT treatment also reduced wound infiltrating macrophage numbers. In conclusion, DHT treatment facilitates local wound healing by accelerating the resolution of inflammation, but not through alterations of post-burn hypermetabolic response.
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Affiliation(s)
- Huaikai Shi
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (H.S.); (D.M.); (B.C.); (B.L.); (R.J.P.); (Z.L.); (P.K.M.)
| | - Tsun-Ho Lo
- Dendritic Cell Research, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (T.-H.L.); (H.-T.C.); (P.A.S.)
| | - Duncan Ma
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (H.S.); (D.M.); (B.C.); (B.L.); (R.J.P.); (Z.L.); (P.K.M.)
| | - Brenton Condor
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (H.S.); (D.M.); (B.C.); (B.L.); (R.J.P.); (Z.L.); (P.K.M.)
| | - Brian Lesmana
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (H.S.); (D.M.); (B.C.); (B.L.); (R.J.P.); (Z.L.); (P.K.M.)
| | - Roxanne J Parungao
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (H.S.); (D.M.); (B.C.); (B.L.); (R.J.P.); (Z.L.); (P.K.M.)
| | - Kevin H.-Y. Tsai
- Adrenal Steroids Laboratory, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (K.H.-Y.T.); (M.S.C.)
| | - Sarah Kim
- Bone Biology Group, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia;
| | - Hsiao-Ting Chen
- Dendritic Cell Research, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (T.-H.L.); (H.-T.C.); (P.A.S.)
| | - Pablo A Silveira
- Dendritic Cell Research, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (T.-H.L.); (H.-T.C.); (P.A.S.)
| | - Zhe Li
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (H.S.); (D.M.); (B.C.); (B.L.); (R.J.P.); (Z.L.); (P.K.M.)
- Burns Unit, Concord Repatriation General Hospital, Sydney 2139, Australia
| | - Mark S Cooper
- Adrenal Steroids Laboratory, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (K.H.-Y.T.); (M.S.C.)
| | - Ulla Simanainen
- Andrology Laboratory, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (U.S.); (D.J.H.)
| | - David J Handelsman
- Andrology Laboratory, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (U.S.); (D.J.H.)
| | - Peter K Maitz
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (H.S.); (D.M.); (B.C.); (B.L.); (R.J.P.); (Z.L.); (P.K.M.)
- Burns Unit, Concord Repatriation General Hospital, Sydney 2139, Australia
| | - Yiwei Wang
- Burns Research and Reconstructive Surgery, ANZAC Research Institute, University of Sydney, Sydney 2139, Australia; (H.S.); (D.M.); (B.C.); (B.L.); (R.J.P.); (Z.L.); (P.K.M.)
- Correspondence: ; Tel.: +61-2-9767-9825
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7
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Chong C, Wang Y, Fathi A, Parungao R, Maitz PK, Li Z. Skin wound repair: Results of a pre-clinical study to evaluate electropsun collagen-elastin-PCL scaffolds as dermal substitutes. Burns 2019; 45:1639-1648. [PMID: 31076208 DOI: 10.1016/j.burns.2019.04.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 04/11/2019] [Accepted: 04/16/2019] [Indexed: 01/18/2023]
Abstract
The gold standard treatment for severe burn injuries is autologous skin grafting and the use of commercial dermal substitutes. However, resulting skin tissue following treatment usually displays abnormal morphology and functionality including scarring, skin contracture due to the poor elasticity and strength of existing dermal substitutes. In this study, we have developed a triple-polymer scaffold made of collagen-elastin-polycaprolactone (CEP) composite, aiming to enhance the mechanical properties of the scaffold while retaining its biological properties in promoting cell attachment, proliferation and tissue regeneration. The inclusion of elastin was revealed to decrease the stiffness of the scaffold, while also decreasing hysteresis and increasing elasticity. In mice, electrospun collagen-elastin-PCL scaffolds promoted keratinocyte and fibroblast proliferation, tissue integration and accelerated early-stage angiogenesis. Only a mild inflammatory response was observed in the first 2 weeks post-subcutaneous implantation. Our data indicates that the electrospun collagen-elastin-PCL scaffolds could potentially serve as a skin substitute to promote skin cell growth and tissue regeneration after severe burn injury.
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Affiliation(s)
- Cassandra Chong
- Burns Research Group, ANZAC Research Institute, Concord Hospital, University of Sydney, Concord West, NSW 2139, Australia
| | - Yiwei Wang
- Burns Research Group, ANZAC Research Institute, Concord Hospital, University of Sydney, Concord West, NSW 2139, Australia; Disciplines of Surgery, School of Medicine, University of Sydney, NSW 2006, Australia
| | - Ali Fathi
- School of Chemical and Biomolecular Engineering, University of Sydney, NSW 2006, Australia
| | - Roxanne Parungao
- Burns Research Group, ANZAC Research Institute, Concord Hospital, University of Sydney, Concord West, NSW 2139, Australia
| | - Peter K Maitz
- Burns Research Group, ANZAC Research Institute, Concord Hospital, University of Sydney, Concord West, NSW 2139, Australia; Disciplines of Surgery, School of Medicine, University of Sydney, NSW 2006, Australia; Burns and Reconstructive Surgery Unit, Concord Hospital, Concord, NSW 2139, Australia
| | - Zhe Li
- Burns Research Group, ANZAC Research Institute, Concord Hospital, University of Sydney, Concord West, NSW 2139, Australia; Disciplines of Surgery, School of Medicine, University of Sydney, NSW 2006, Australia; Burns and Reconstructive Surgery Unit, Concord Hospital, Concord, NSW 2139, Australia.
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8
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Clayton NA, Haertsch PA, Maitz PK, Issler-Fisher AC. Ablative Fractional Resurfacing in Acute Care Management of Facial Burns: A New Approach to Minimize the Need for Acute Surgical Reconstruction. J Burn Care Res 2019; 40:368-372. [DOI: 10.1093/jbcr/irz030] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Nicola A Clayton
- Speech Pathology Department, Concord Repatriation General Hospital, Sydney, Australia
- Burns Unit, Concord Repatriation General Hospital, Sydney, Australia
- School of Health & Rehabilitation Sciences, University of Queensland, Brisbane, Australia
| | - Peter A Haertsch
- Speech Pathology Department, Concord Repatriation General Hospital, Sydney, Australia
| | - Peter K Maitz
- Speech Pathology Department, Concord Repatriation General Hospital, Sydney, Australia
- Faculty of Medicine, University of Sydney, Australia
| | - Andrea C Issler-Fisher
- Speech Pathology Department, Concord Repatriation General Hospital, Sydney, Australia
- Faculty of Medicine, University of Sydney, Australia
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9
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Manavitehrani I, Le TY, Daly S, Wang Y, Maitz PK, Schindeler A, Dehghani F. Formation of porous biodegradable scaffolds based on poly(propylene carbonate) using gas foaming technology. Materials Science and Engineering: C 2019; 96:824-830. [DOI: 10.1016/j.msec.2018.11.088] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 11/20/2018] [Accepted: 11/30/2018] [Indexed: 10/27/2022]
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10
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Clayton NA, Nicholls CM, Blazquez K, Brownlow C, Maitz PK, Fisher OM, Issler-Fisher AC. Dysphagia in older persons following severe burns: Burn location is irrelevant to risk of dysphagia and its complications in patients over 75 years. Burns 2018; 44:1997-2005. [PMID: 30107942 DOI: 10.1016/j.burns.2018.07.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 06/14/2018] [Accepted: 07/19/2018] [Indexed: 12/31/2022]
Abstract
BACKGROUND Management of burns in older persons is complex with evidence indicating advanced age is associated with elevated risk for morbidity and mortality. Dysphagia and its sequelae may further increase this risk. AIMS (1) Determine the prevalence, and (2) identify risk factors for dysphagia in patients admitted with severe burn injury over 75 years. METHODS All patients >75 years admitted to Concord Repatriation General Hospital with severe burn injury over a 4-year period (2013-2017) were assessed for dysphagia on presentation and continually monitored throughout their admission. Burn injury, demographic and nutritional data were captured and analysed for association with and predictive value for dysphagia. RESULTS Sixty-six patients (35 male; 31 female) aged 75-96 years (median 82 years) were recruited. Dysphagia was identified in 46.97% during their hospital admission. Dysphagia was significantly associated with burn size, pre-existing cognitive impairment, mechanical ventilation, duration of enteral feeding, hospital length of stay, in-hospital complications and mortality. No association was identified between burn location, burn mechanism, surgery and dysphagia. Burn size and Malnutrition Screening Tool score were found to be independent predictors for dysphagia. CONCLUSIONS Dysphagia prevalence is high in older persons with burns and is associated with increased morbidity and mortality, regardless of burn location.
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Affiliation(s)
- Nicola A Clayton
- Speech Pathology Department, Concord Repatriation General Hospital, NSW, Australia; Burns Unit, Concord Repatriation General Hospital, NSW 2139, Australia; School of Health & Rehabilitation Sciences, University of Queensland, QLD, Australia.
| | - Caroline M Nicholls
- Burns Unit, Concord Repatriation General Hospital, NSW 2139, Australia; Nutrition & Dietetics Department, Concord Repatriation General Hospital, NSW, Australia
| | - Karen Blazquez
- Speech Pathology Department, Concord Repatriation General Hospital, NSW, Australia
| | - Cheryl Brownlow
- Burns Unit, Concord Repatriation General Hospital, NSW 2139, Australia; Nutrition & Dietetics Department, Concord Repatriation General Hospital, NSW, Australia
| | - Peter K Maitz
- Burns Unit, Concord Repatriation General Hospital, NSW 2139, Australia; Faculty of Medicine, University of Sydney, Sydney, NSW, Australia
| | - Oliver M Fisher
- UNSW Department of Surgery, St George Hospital, Sydney, NSW, Australia
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11
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Mithieux SM, Aghaei-Ghareh-Bolagh B, Yan L, Kuppan KV, Wang Y, Garces-Suarez F, Li Z, Maitz PK, Carter EA, Limantoro C, Chrzanowski W, Cookson D, Riboldi-Tunnicliffe A, Baldock C, Ohgo K, Kumashiro KK, Edwards G, Weiss AS. Tropoelastin Implants That Accelerate Wound Repair. Adv Healthc Mater 2018; 7:e1701206. [PMID: 29450975 DOI: 10.1002/adhm.201701206] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 01/14/2018] [Indexed: 11/12/2022]
Abstract
A novel, pure, synthetic material is presented that promotes the repair of full-thickness skin wounds. The active component is tropoelastin and leverages its ability to promote new blood vessel formation and its cell recruiting properties to accelerate wound repair. Key to the technology is the use of a novel heat-based, stabilized form of human tropoelastin which allows for tunable resorption. This implantable material contributes a tailored insert that can be shaped to the wound bed, where it hydrates to form a conformable protein hydrogel. Significant benefits in the extent of wound healing, dermal repair, and regeneration of mature epithelium in healthy pigs are demonstrated. The implant is compatible with initial co-treatment with full- and split-thickness skin grafts. The implant's superiority to sterile bandaging, commercial hydrogel and dermal regeneration template products is shown. On this basis, a new concept for a prefabricated tissue repair material for point-of-care treatment of open wounds is provided.
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Affiliation(s)
- Suzanne M. Mithieux
- School of Life and Environmental Sciences; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
| | - Behnaz Aghaei-Ghareh-Bolagh
- School of Life and Environmental Sciences; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
| | - Leping Yan
- School of Life and Environmental Sciences; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
| | - Kekini V. Kuppan
- School of Life and Environmental Sciences; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
- Heart Research Institute; University of Sydney; NSW 2006 Australia
| | - Yiwei Wang
- Burns Research Group; ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
| | - Francia Garces-Suarez
- Burns Research Group; ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
| | - Zhe Li
- Burns Research Group; ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
| | - Peter K. Maitz
- Burns Research Group; ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
| | - Elizabeth A. Carter
- Vibrational Spectroscopy Core Facility and Faculty of Chemistry; University of Sydney; NSW 2006 Australia
| | - Christina Limantoro
- Faculty of Pharmacy; University of Sydney; NSW 2006 Australia
- Australian Institute for Nanoscale Science and Technology; University of Sydney; NSW 2006 Australia
| | - Wojciech Chrzanowski
- Faculty of Pharmacy; University of Sydney; NSW 2006 Australia
- Australian Institute for Nanoscale Science and Technology; University of Sydney; NSW 2006 Australia
| | | | | | - Clair Baldock
- Wellcome Trust Centre for Cell-Matrix Research; Division of Cell Matrix Biology and Regenerative Medicine; School of Biological Sciences; Manchester Academic Health Centre; University of Manchester; Manchester M13 9PT UK
| | - Kosuke Ohgo
- Department of Chemistry; University of Hawaii; Honolulu HI 96822 USA
| | | | - Glenn Edwards
- School of Animal and Veterinary Sciences; Charles Sturt University; NSW 2678 Australia
| | - Anthony S. Weiss
- School of Life and Environmental Sciences; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
- Bosch Institute; University of Sydney; NSW 2006 Australia
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12
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Dai NT, Chang HI, Wang YW, Fu KY, Huang TC, Huang NC, Li JK, Hsieh PS, Dai LG, Hsu CK, Maitz PK. Restoration of skin pigmentation after deep partial or full-thickness burn injury. Adv Drug Deliv Rev 2018; 123:155-164. [PMID: 29079536 DOI: 10.1016/j.addr.2017.10.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/28/2017] [Accepted: 10/17/2017] [Indexed: 12/18/2022]
Abstract
Significant skin pigmentation changes occur when patients suffer deep burn injuries. These pigmentation disorders may cause not only cosmetic and psychological issues, but more importantly it increases the risk of skin cancer or photoaging. Severe burns significantly effect on the process of repigmentation as the pigmentation is tightly regulated by cell proliferation and differentiation of melanocytes and melanocyte stem cells which are housing in the epidermis and hair follicles of the skin. In the present review, we discuss the possible mechanisms to replenish the melanocytes from the healthy epidermis and hair follicles surrounding burn wounds. The molecular mechanisms of skin repigmentation following healing of burn injuries includes the differentiation of melanoblasts into melanocytes, the distribution and responses of melanocytes and melanocyte stem cells after burn injury, and the regulation of melanin production. We also reviewed advanced therapeutic strategies to treat pigmentation disorders, such as convectional surgery, laser, UV treatment and emerging concepts in skin tissue-engineering.
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13
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Manavitehrani I, Fathi A, Wang Y, Maitz PK, Mirmohseni F, Cheng TL, Peacock L, Little DG, Schindeler A, Dehghani F. Fabrication of a Biodegradable Implant with Tunable Characteristics for Bone Implant Applications. Biomacromolecules 2017; 18:1736-1746. [DOI: 10.1021/acs.biomac.7b00078] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Iman Manavitehrani
- The University of Sydney, School of Chemical
and Biomolecular Engineering, Sydney, 2006, Australia
| | - Ali Fathi
- The University of Sydney, School of Chemical
and Biomolecular Engineering, Sydney, 2006, Australia
| | - Yiwei Wang
- Burns
Research Group, ANZAC Research Institute, University of Sydney, Concord, New South Wales 2139, Australia
| | - Peter K. Maitz
- Burns
Research Group, ANZAC Research Institute, University of Sydney, Concord, New South Wales 2139, Australia
- Burns
and Reconstructive Surgery Unit, Concord Repatriation General Hospital, Concord, New South Wales 2139, Australia
| | - Farid Mirmohseni
- The University of Sydney, School of Chemical
and Biomolecular Engineering, Sydney, 2006, Australia
- Orthopaedic
Research and Biotechnology, The Children’s Hospital at Westmead, Westmead, 2145, Australia
| | - Tegan L. Cheng
- Orthopaedic
Research and Biotechnology, The Children’s Hospital at Westmead, Westmead, 2145, Australia
| | - Lauren Peacock
- Orthopaedic
Research and Biotechnology, The Children’s Hospital at Westmead, Westmead, 2145, Australia
| | - David G. Little
- Orthopaedic
Research and Biotechnology, The Children’s Hospital at Westmead, Westmead, 2145, Australia
- Paediatrics
and Child Health, University of Sydney, Sydney, 2006, Australia
| | - Aaron Schindeler
- Orthopaedic
Research and Biotechnology, The Children’s Hospital at Westmead, Westmead, 2145, Australia
- Paediatrics
and Child Health, University of Sydney, Sydney, 2006, Australia
| | - Fariba Dehghani
- The University of Sydney, School of Chemical
and Biomolecular Engineering, Sydney, 2006, Australia
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14
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Negahi Shirazi A, Fathi A, Suarez FG, Wang Y, Maitz PK, Dehghani F. A Novel Strategy for Softening Gelatin-Bioactive-Glass Hybrids. ACS Appl Mater Interfaces 2016; 8:1676-1686. [PMID: 26727696 DOI: 10.1021/acsami.5b09006] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The brittle structure of polymer-bioactive-glass hybrids is a hurdle for their biomedical applications. To address this issue here, we developed a novel method to cease the overcondensation of bioactive-glass by polymer cross-linking. Here, an organosilane-functionalized gelatin methacrylate (GelMA) is covalently bonded to a bioactive-glass during the sol-gel process, and the condensation of silica networks is controlled by photo-cross-linking of GelMA. The physicochemical properties and mechanical strength of these hybrids are tunable by the incorporation of secondary cross-linking agents. These hydrogels display elastic properties with ultimate compression strain above 0.2 mm·mm(-1) and tunable compressive modulus in the range of 42-530 kPa. In addition, these hydrogels are bioactive because they promoted the alkaline phosphatase activity of bone progenitor cells. They are also well-tolerated in the mice subcutaneous model. Therefore, our method is efficient for the prevention of overcondensation and allows preparation of soft bioactive hydrogels from organic-inorganic matrices, suitable for soft and hard tissue regeneration.
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Affiliation(s)
- Ali Negahi Shirazi
- School of Chemical & Biomolecular Engineering, University of Sydney , Sydney, New South Wales 2006, Australia
| | - Ali Fathi
- School of Chemical & Biomolecular Engineering, University of Sydney , Sydney, New South Wales 2006, Australia
| | | | | | | | - Fariba Dehghani
- School of Chemical & Biomolecular Engineering, University of Sydney , Sydney, New South Wales 2006, Australia
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15
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Manavitehrani I, Fathi A, Wang Y, Maitz PK, Dehghani F. Reinforced Poly(Propylene Carbonate) Composite with Enhanced and Tunable Characteristics, an Alternative for Poly(lactic Acid). ACS Appl Mater Interfaces 2015; 7:22421-22430. [PMID: 26376751 DOI: 10.1021/acsami.5b06407] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The acidic nature of the degradation products of polyesters often leads to unpredictable clinical complications, such as necrosis of host tissues and massive immune cell invasions. In this study, poly(propylene carbonate) (PPC) and starch composite is introduced with superior characteristics as an alternative to polyester-based polymers. The degradation products of PPC-starch composites are mainly carbon dioxide and water; hence, the associated risks to the acidic degradation of polyesters are minimized. Moreover, the compression strength of PPC-starch composites can be tuned over the range of 0.2±0.03 MPa to 33.9±1.51 MPa by changing the starch contents of composites to address different clinical needs. More importantly, the addition of 50 wt % starch enhances the thermal processing capacity of the composites by elevating their decomposition temperature from 245 to 276 °C. Therefore, thermal processing methods, such as extrusion and hot melt compression methods can be used to generate different shapes and structures from PPC-starch composites. We also demonstrated the cytocompatibility and biocompatibility of these composites by conducting in vitro and in vivo tests. For instance, the numbers of osteoblast cells were increased 2.5 fold after 7 days post culture. In addition, PPC composites in subcutaneous mice model resulted in mild inflammatory responses (e.g., the formation of fibrotic tissue) that were diminished from two to 4 weeks postimplantation. The long-term in vivo biodegradation of PPC composites are compared with poly(lactic acid) (PLA). The histochemical analysis revealed that after 8 weeks, the biodegradation of PLA leads to massive immune cell infusion and inflammation at the site, whereas the PPC composites are well-tolerated in vivo. All these results underline the favorable properties of PPC-starch composites as a benign biodegradable biomaterial for fabrication of biomedical implants.
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Affiliation(s)
- Iman Manavitehrani
- School of Chemical and Biomolecular Engineering, University of Sydney , Sydney, New South Wales 2006, Australia
| | - Ali Fathi
- School of Chemical and Biomolecular Engineering, University of Sydney , Sydney, New South Wales 2006, Australia
| | - Yiwei Wang
- Burns Research Group, ANZAC Research Institute, University of Sydney , Concord, New South Wales 2139, Australia
| | - Peter K Maitz
- Burns Research Group, ANZAC Research Institute, University of Sydney , Concord, New South Wales 2139, Australia
- Burns and Reconstructive Surgery Unit, Concord Repatriation General Hospital , Concord, New South Wales 2139, Australia
| | - Fariba Dehghani
- School of Chemical and Biomolecular Engineering, University of Sydney , Sydney, New South Wales 2006, Australia
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16
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Wang Y, Mithieux SM, Kong Y, Wang XQ, Chong C, Fathi A, Dehghani F, Panas E, Kemnitzer J, Daniels R, Kimble RM, Maitz PK, Li Z, Weiss AS. Tropoelastin incorporation into a dermal regeneration template promotes wound angiogenesis. Adv Healthc Mater 2015; 4:577-84. [PMID: 25469903 DOI: 10.1002/adhm.201400571] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Revised: 11/05/2014] [Indexed: 11/06/2022]
Abstract
Severe burn injury results in substantial skin loss and cannot be treated by autografts. The Integra Dermal Regeneration Template (IDRT) is the leading synthetic skin substitute because it allows for wound bed regeneration and wound healing. However, all substitutes suffer from slow blood vessel ingrowth and would benefit considerably from enhanced vascularization to nurture tissue repair. It is shown here that by incorporating the human elastic protein tropoelastin into a dermal regeneration template (TDRT) we can promote angiogenesis in wound healing. In small and large animal models comprising mice and pigs, the hybrid TDRT biomaterial and IDRT show similar contraction to autografts and decrease wound contraction compared to open wounds. In mice, TDRT accelerates early stage angiogenesis by 2 weeks, as evidenced by increased angiogenesis fluorescent radiant efficiency in live animal imaging and the expression of endothelial cell adhesion marker CD146. In the pig, a full thickness wound repair model confirms increased numbers of blood vessels in the regenerating areas of the dermis closest to the hypodermis and immediately below the epidermis at 2 weeks post-surgery. It is concluded that including tropoelastin in a dermal regeneration template has the potential to promote wound repair through enhanced vascularization.
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Affiliation(s)
- Yiwei Wang
- Burns Research Group, ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
| | - Suzanne M. Mithieux
- School of Molecular Bioscience; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
| | - Yvonne Kong
- School of Molecular Bioscience; University of Sydney; NSW 2006 Australia
| | - Xue-Qing Wang
- Centre for Children's Burns and Trauma Research, Queensland Children's Medical Research Institute; University of Queensland; Australia
- Stuart Pegg Paediatric Burns Centre; Royal Children's Hospital; Brisbane Australia
| | - Cassandra Chong
- Burns Research Group, ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
| | - Ali Fathi
- School of Chemical and Biomolecular Engineering; University of Sydney; NSW 2006 Australia
| | - Fariba Dehghani
- School of Chemical and Biomolecular Engineering; University of Sydney; NSW 2006 Australia
| | | | | | | | - Roy M. Kimble
- Centre for Children's Burns and Trauma Research, Queensland Children's Medical Research Institute; University of Queensland; Australia
- Stuart Pegg Paediatric Burns Centre; Royal Children's Hospital; Brisbane Australia
| | - Peter K. Maitz
- Burns Research Group, ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
- Burns and Reconstructive Surgery Unit; Concord Repatriation General Hospital; NSW 2139 Australia
| | - Zhe Li
- Burns Research Group, ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
- Burns and Reconstructive Surgery Unit; Concord Repatriation General Hospital; NSW 2139 Australia
| | - Anthony S. Weiss
- School of Molecular Bioscience; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
- Bosch Institute; University of Sydney; NSW 2006 Australia
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17
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Wang Y, Mithieux SM, Kong Y, Wang XQ, Chong C, Fathi A, Dehghani F, Panas E, Kemnitzer J, Daniels R, Kimble RM, Maitz PK, Li Z, Weiss AS. Wound Healing: Tropoelastin Incorporation into a Dermal Regeneration Template Promotes Wound Angiogenesis (Adv. Healthcare Mater. 4/2015). Adv Healthc Mater 2015. [DOI: 10.1002/adhm.201570024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yiwei Wang
- Burns Research Group, ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
| | - Suzanne M. Mithieux
- School of Molecular Bioscience; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
| | - Yvonne Kong
- School of Molecular Bioscience; University of Sydney; NSW 2006 Australia
| | - Xue-Qing Wang
- Centre for Children's Burns and Trauma Research, Queensland Children's Medical Research Institute; University of Queensland; Australia
- Stuart Pegg Paediatric Burns Centre; Royal Children's Hospital; Brisbane Australia
| | - Cassandra Chong
- Burns Research Group, ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
| | - Ali Fathi
- School of Chemical and Biomolecular Engineering; University of Sydney; NSW 2006 Australia
| | - Fariba Dehghani
- School of Chemical and Biomolecular Engineering; University of Sydney; NSW 2006 Australia
| | | | | | | | - Roy M. Kimble
- Centre for Children's Burns and Trauma Research, Queensland Children's Medical Research Institute; University of Queensland; Australia
- Stuart Pegg Paediatric Burns Centre; Royal Children's Hospital; Brisbane Australia
| | - Peter K. Maitz
- Burns Research Group, ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
- Burns and Reconstructive Surgery Unit; Concord Repatriation General Hospital; NSW 2139 Australia
| | - Zhe Li
- Burns Research Group, ANZAC Research Institute; University of Sydney; Concord NSW 2139 Australia
- Burns and Reconstructive Surgery Unit; Concord Repatriation General Hospital; NSW 2139 Australia
| | - Anthony S. Weiss
- School of Molecular Bioscience; University of Sydney; NSW 2006 Australia
- Charles Perkins Centre; University of Sydney; NSW 2006 Australia
- Bosch Institute; University of Sydney; NSW 2006 Australia
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19
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Abstract
In October 2002, a terrorist attack on a nightclub in Bali resulted in an explosion and fire, causing the deaths of more than 200 people, including 88 Australian citizens. After first aid and primary care, the injured were repatriated to Darwin for triage and continued treatment and were then disseminated to various burn units throughout Australia. At the Repatriation General Hospital Concord Sydney, we received 12 patients with burns and a variety of blast injuries. Their treatment was complicated by infection with multiresistant organisms that were previously unseen in our unit and the presence of complex shrapnel wounds. There were no deaths and, with two exceptions, all patients were discharged within 6 weeks. This incident had profound effects on our unit, particularly related to the management of high-velocity shrapnel injuries, serious ongoing septic complications, and the psychological effects on both patients and staff, all of which are detailed and discussed.
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Affiliation(s)
- Peter J Kennedy
- Burns Unit, Concord Repatriation General Hospital, Concord, Australia
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20
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Abstract
Flap prefabrication is dependent on the neovascular response that occurs between the implanted arteriovenous pedicle and the recipient tissue. Augmentation of this neovascular response with angiogenic growth factors would maximize flap survival and minimize the interval between pedicle implantation and flap rotation. Maximizing the biologic activity of endogenous growth factors would likewise positively impact upon flap survival. This study examined the role of basic fibroblast growth factor, a known potent angiogenic growth factor, on flap survival in a rabbit ear prefabrication model. Sucrose octasulfate, a substance that binds basic fibroblast growth factor, stabilizes it, and protects it from degradation, was also studied to determine its impact on flap survival. Flap survival was increased using basic fibroblast growth factor, sucrose octasulfate, and the two substances combined together. The use of substrates designed to maximize the biologic activity of endogenous growth factors, rather than relying on the artificial addition of exogenous growth factors, represents a new approach in the search for methods that will improve flap survival.
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Affiliation(s)
- F J Duffy
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, MA 02115-6195, USA
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21
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Maitz PK, Trickett RI, Dekker P, Tos P, Dawes JM, Piper JA, Lanzetta M, Owen ER. Sutureless microvascular anastomoses by a biodegradable laser-activated solid protein solder. Plast Reconstr Surg 1999; 104:1726-31. [PMID: 10541175 DOI: 10.1097/00006534-199911000-00017] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A new sutureless technique to successfully anastomose the abdominal aorta of rats (1.3 mm in diameter) by using a fully biodegradable, laser-activated protein solder is presented. A total of 90 rats were divided into two groups randomly. In group one, the anastomoses were performed by using conventional microsuturing technique, whereas in group two, the anastomoses were performed by using a new laser welding technique. In addition, each of the two groups were divided into five subgroups and evaluated at different follow-up periods (10 minutes, 1 hour, 1 day, 1 week, and 6 weeks). At these intervals, the anastomoses were evaluated for patency and tensile strength. Three anastomoses in each subgroup were processed for light and electron microscopy. All anastomoses were found to be patent. The mean clamp time of the anastomoses performed with conventional suturing was 20.6 minutes compared with 7.2 minutes for the laser-activated welded anastomoses (p < 0.001). The strain measurements showed a stronger mechanical bond of the sutured anastomoses in the initial phase. However, at 6 weeks the tensile strength of the laser-welded anastomoses was higher compared with the conventional suture technique. Histologic evaluations revealed a near complete resorption of the solder after 6 weeks. The junction site of the vessel ends cannot be determined on the luminal side of the artery. In conclusion, a resorbable protein used as a solder, activated by a diode laser, can provide a reliable, safe, and rapid arterial anastomosis, which could be performed by any microsurgeon faster than conventional suturing after a short learning curve.
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Affiliation(s)
- P K Maitz
- Microsearch Foundation of Australia, the Centre for Lasers and Applications, Macquarie University Sydney, NSW, Australia.
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22
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Abstract
In this study, a unilateral epigastric free flap was raised in 12 rabbits. After the arterial portion of the flap (the superficial femoral artery) was replaced by a 1-cm-long polytetrafluoroethylene graft with an internal diameter of 1 mm, the flap was revascularized by two conventional microvascular end-to-end anastomoses (graft to artery and vein to vein). At 3 weeks, all flaps were raised again and the patency of the polytetrafluoroethylene grafts was checked. All grafts, including the proximal and distal anastomoses, were harvested and processed for light and electron microscopy. All grafts remained patient, and all flaps survived the period of 3 weeks. At reexploration, the graft was completely covered with connective tissue. Light and scanning electron microscopy evaluation showed that the internal surface of the graft was covered by a fibrin layer, and that the ingrowth of neoendothelium had just started from both anastomotic sites. The use of small-diameter polytetrafluoroethylene grafts in a rabbit free-flap model was demonstrated to be a reliable alternative for pedicle elongation.
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Affiliation(s)
- P K Maitz
- Microsearch Foundation of Australia, Sydney
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Knabl JS, Maitz PK, Deutinger M, Millesi H, Meissl G. [Analysis of hand function with the Millesi examination scale in patients with pollicisation after aplasia or hypoplasia of the thumb]. HANDCHIR MIKROCHIR P 1998; 30:317-24. [PMID: 9816513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Pollicisation of a single long finger is the method of choice to treat congenital thumb aplasia or thumb hypoplasia. Using Millesi's scale for the functional analysis of the hand, we examined six patients treated in the years 1983 to 1994 in our service. Average age at the time of surgery was 2.4 years and the follow-up time was seven years on average. Of the six patients, four suffered from additional malformations of the ipsilateral arm. These anomalies required early surgical treatment and therefore delayed the pollicisation procedure. The results of the anatomical part of the examination ranged between 39 and 94% of the achievable value. The final results including sensibility, strength, and skills reached 11 to 50%. Development of skills and muscle strength in the operated hand was dependent on the follow-up time. Millesi's scale could be applied successfully in this special group of children with congenital malformation of hands.
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Affiliation(s)
- J S Knabl
- Abteilung für Plastische und Wiederherstellungschirurgie, Universitätsklinik Wien
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24
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Abstract
The pharmacodynamics of mivacurium, a new short-acting non-depolarizing muscle relaxant, were studied in nine severely burned patients with concomitant inhalation injury. Complete neuromuscular blockade was achieved within 1.3 min (controls 3.0 min) following the usually recommended intubating dose (0.15 mg/kg/BW 2 x ED95) of mivacurium. The clinical duration of neuromuscular blockade and the recovery times were slightly prolonged, due to significantly reduced serum cholinesterase activity (clinical duration 24.6 min vs. 15.3 min). This pharmacodynamic profile makes mivacurium preferable for intermittent on-demand neuromuscular blockade in the severely burned patient.
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Affiliation(s)
- A E Werba
- Department of Anaesthesia and General Intensive Care, School of Medicine, University of Vienna, Austria
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25
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Abstract
This study was designed to determine whether tissue expansion after vascular pedicle implantation would increase the survival area of prefabricated skin flaps. In 20 New Zealand white rabbits, the vascular pedicle consisting of the central artery and vein of the left ear was implanted into the neck. At the time of pedicle implantation a subcutaneous pocket was created measuring 5 x 14 cm beneath the implantation site. Tissue expanders of three different sizes and volumes were implanted in the rabbits of three treatment groups. No tissue expander was implanted in the animals of the control group. All flaps were transposed after 3 weeks to the contralateral ear, and flap survival was assessed 1 week later. The increased area of the flap survival was statistically significant in all three treatment groups compared to the nonexpanded flaps (P = 0.003, P = 0.004, P < 0.0001, respectively). In addition there was a statistically significant larger area of survival using a 100-cc expander measuring 5 x 14 cm (the same size as the elevated flap) compared to 40-cc (3 x 5 cm) or to 60-cc (4 x 8 cm) expanders (P < 0.001, P = 0.004, respectively). The one-way analysis of variance and the t-test were used to show statistical differences. We conclude that the time necessary for neovascularisation of the skin flap could be used to expand the tissue, not only increasing the amount of available tissue, but also enhancing the vascularity.
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Affiliation(s)
- P K Maitz
- Division of Plastic Surgery, Brigham/Children's/Harvard, Boston Massachusetts, USA
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Pribaz JJ, Maitz PK, Fine NA. Flap prefabrication using the "vascular crane" principle: an experimental study and clinical application. Br J Plast Surg 1994; 47:250-6. [PMID: 8081613 DOI: 10.1016/0007-1226(94)90007-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Techniques for tissue transfer have continued to evolve. Free flap prefabrication represents a further progression of well known plastic surgery principles in the arena of tissue transfer. This report presents an experimental study demonstrating that the repeated use of a vascular pedicle to prefabricate flaps in the rabbit is possible. There is a decrease in flap viability with the second transfer. A clinical case using this repeated transfer or "crane" principle is also reported. We conclude that the repeated use of a vascular pedicle to prefabricate multiple flaps is a viable option in selected cases.
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Affiliation(s)
- J J Pribaz
- Brigham/Children's/Harvard Division of Plastic Surgery, Boston, Massachusetts
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27
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Maitz PK, Pribaz JJ, Duffy FJ, Hergrueter CA. The value of the delay phenomenon in flap prefabrication: an experimental study in rabbits. Br J Plast Surg 1994; 47:149-54. [PMID: 8193849 DOI: 10.1016/0007-1226(94)90044-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Neovascularisation of thin skin flaps after arteriovenous pedicle implantation (flap prefabrication) and the impact of the delay mechanism on the viability of these flaps were investigated. Twenty-four full thickness skin flaps were raised in twelve New Zealand white rabbits. Delay incisions were made at the lateral borders of the planned flaps at the same time as pedicle implantation, 1 week before pedicle implantation, or 1 week after pedicle implantation and the flaps based on the implanted vessels raised at 2 weeks after implantation. Flap survival assessed at 1 week was found to be improved when flap delay was performed 1 week before or after pedicle implantation. Angiographic studies demonstrated an increased density and linearity of the vascular pattern in these delay group flaps. The combination of the time-tested concept of delaying a flap with the newer technique of flap prefabrication appears to improve flap viability.
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Affiliation(s)
- P K Maitz
- Brigham and Women's Hospital, Boston
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28
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Abstract
As flap prefabrication becomes a more commonly used clinical tool, it is necessary to investigate the limitations of this technique. Reconstructive procedures of the face often require "custom fitted" flaps to satisfy esthetic demands. This study examines and compares the safety of manipulating thin prefabricated skin flaps versus established axial pattern skin flaps. Twenty-seven New Zealand white rabbits were used to determine if prefabricated flaps can be folded 180 degrees around the edge of the rabbits' ears. The survival of these folded prefabricated flaps was compared with the survival of axial pattern flaps sutured into an identically recipient site. In addition, flaps prefabricated in the same manner were sutured onto a straight recipient bed to evaluate the viability of the newly vascularized tissue. The folded prefabricated flaps had reduced survival (56%) compared to equivalent folded axial pattern flaps (85%), P < 0.005. The nonmanipulated prefabricated flaps and axial pattern flaps survived completely.
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Affiliation(s)
- P K Maitz
- Division of Plastic Surgery, Brigham and Women's Hospital, Boston, MA 02115
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29
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Abstract
We have developed a new model of thin flap prefabrication in the rabbit with an exteriorised vascular pedicle in a skin tube. Study of these prefabricated flaps after transfer demonstrated that distal flap survival improved as the interval between implantation and flap transfer increased. Exteriorising the pedicle minimises both donor deformity and pedicle trauma and allows easier experimental study of the neovascularisation process in flap prefabrication.
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Affiliation(s)
- F J Duffy
- Brigham/Children's/Harvard Division of Plastic Surgery, Boston
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