Electrospinning of natural polymers for the production of nanofibres for wound healing applications

Wound healing is a highly regulated process composed of four overlapping phases: (1) coagulation/haemostasis, (2) inflammation, (3) proliferation and (4) remodelling. Comorbidities such as advanced age, diabetes and obesity can impair natural tissue repair, rendering the wound in a pathological state of inflammation. This results in significant discomfort for patients and considerable financial costs for healthcare systems. Due to the complex nature of wound healing, current treatments are ineffective at dealing with delayed healing. With flexible properties that can be tailored, nanomaterials have emerged as alternative therapeutics for many biomedical applications. A nanofibrous network can be made via electrospinning polymers using a high electric field to create a responsive meshwork that can be used as a medical dressing. A nanofibrous device has properties that can overcome the limitations of traditional dressings, such as: (1) adaptability to wound contour; (2) controlled drug delivery of therapeutics; (3) gaseous exchange; (4) exudate absorption and (5) surface functionalisation to further enhance the biological activity of the dressing. This review details emerging trends in nanotechnology to specifically target wound healing applications. Particular focus is given to the most common natural polymers that could address many unmet healthcare needs.

Structural Variants of a Liver Fluke Derived Granulin Peptide Potently Stimulate Wound Healing

Granulins are a family of growth factors involved in cell proliferation. The liver-fluke granulin, Ov-GRN-1, isolated from a carcinogenic liver fluke Opisthorchis viverrini, can significantly accelerate wound repair in vivo and in vitro. However, it is difficult to express Ov-GRN-1 in recombinant form at high yield, impeding its utility as a drug lead. Previously we reported that a truncated analogue ( Ov-GRN_{12-35_3s}) promotes healing of cutaneous wounds in mice. NMR analysis of this analogue indicates the presence of multiple conformations, most likely as a result of proline cis/ trans isomerization. To further investigate whether the proline residues are involved in adopting the multiple confirmations, we have synthesized analogues involving mutation of the proline residues. We have shown that the proline residues have a significant influence on the structure, activity, and folding of Ov-GRN_{12-35_3s}. These results provide insight into improving the oxidative folding yield and bioactivity of Ov-GRN_{12-35_3s} and might facilitate the development of a novel wound healing agent.

The humanistic and economic burden of chronic wounds: a protocol for a systematic review

BACKGROUND

Chronic non-healing wounds present a substantial economic burden to healthcare system; significant reductions in quality of life for those affected, and precede often serious events such as limp amputations or even premature deaths. This burden is also likely to increase with a larger proportion of elderly and increasing prevalence of life-style diseases such as obesity and diabetes. Reviews of the evidence on the burden of illness associated with chronic wounds have not been comprehensive in scope and have not provided an assessment of the distribution of the health care costs across categories of resource use.

METHODS/DESIGN

This study is a systematic review of multiple databases for studies on adult patients with chronic wounds and with the primary objective to assess the impact on health-related quality of life by category of ulcers, and associated direct and indirect costs. Eligible studies will primary be empirical studies evaluating, describing or comparing measurement of quality of life and economic impact. Two reviewers will independently screen titles and abstracts and select studies involving adults with chronic wounds. These investigators will also independently extract data using a pre-designed data extraction form. Differences in applied methodologies and uncertainties will clearly be accounted for. Conservative valuations of costs and impact on health-related quality of life will be prioritised. Variations that may depend on age distribution, the categorisation of ulcer, healthcare system etc. will be described clearly.

DISCUSSION

The proposed systematic review will yield a comprehensive assessment of the humanistic and economic burden of chronic wounds in an adult population. A better understanding of the humanistic and economic burden of chronic wounds is essential for policy and planning purposes, to monitor trends in disease burden and not at least in order to estimate the real-world cost-effectiveness of new treatments and therapies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016037496.

Risk factors for foot ulceration in adults with end-stage renal disease on dialysis: study protocol for a prospective observational cohort study

BACKGROUND

Adults with end-stage renal disease treated with dialysis experience a high burden of foot ulceration and lower extremity amputation. However, the risk factors for foot ulceration in the dialysis population are incompletely understood due to the lack of high-quality prospective evidence. This article outlines the design of a prospective observational cohort study, which aims to investigate the risk factors for foot ulceration in adults on dialysis.

METHODS/DESIGN

This study will recruit 430 participants with end-stage renal disease on dialysis from satellite and home-therapy dialysis units across multiple health organisations in Melbourne, Victoria, Australia. Data collection at baseline will include a participant interview, medical record review, completion of a health-status questionnaire and a non-invasive foot assessment. Twenty participants will also be recruited to a reliability study to evaluate the reproducibility of testing procedures. Primary outcome data includes: new foot ulcer(s). Secondary outcome data includes: number of new foot ulcers, time to onset of new foot ulcer(s), new lower extremity amputation(s), episodes of infection of the foot or lower extremity, episodes of osteomyelitis, foot-related hospitalisations, revascularisation procedure(s) of the lower extremity, new podiatry interventions, kidney transplantation, and mortality. Participants will be assessed at baseline, and at 12 months they will be evaluated for the primary and secondary outcomes. Multivariate Cox proportional hazards models will be used to assess predictors of new foot ulceration and time to event secondary outcomes. Logistic regression will be used for binary outcomes including prevalence of foot ulcerations.

DISCUSSION

This is the first multi-centre prospective observational cohort study to investigate risk factors for foot ulceration in adults with end-stage renal disease on dialysis. This study will improve on prior studies by using prospective methods, multi-centre recruitment, statistical methods to control for confounding variables, and a pre-specified sample size estimation. The findings can inform the design of future trials evaluating the effectiveness of clinical interventions, which may lead to improved patient outcomes in the dialysis setting.

Characteristics of diabetic foot ulcers in Western Sydney, Australia

BACKGROUND

Australia is ranked ninth of 39 countries in the Western Pacific region most affected by diabetes. Patients with diabetes are at high risk of developing foot ulcerations that can develop into non-healing wounds. Recent studies suggest that the lifetime risk of developing a diabetic foot ulcer is as high as 25%. Few studies have reported the prevalence of, risk factors and socioeconomic status associated with, diabetic foot ulcers in Australia. The aim of this study was to evaluate the characteristics of diabetic foot ulcers in a tertiary referral outpatient hospital setting in Western Sydney, Australia.

METHODS

From January-December 2011, a total of 195 outpatients with diabetes were retrospectively extracted for analysis from the Westmead Hospital's Foot Wound Clinic Registry. Data on demographics, socioeconomic status, co-morbidities, foot ulcer characteristics and treatment were recorded on a standardised form.

RESULTS

Demographics and physical characteristics were: 66.2% male, median age 67 years (IQR: 56-76), median body mass index (BMI) of 28 kg/m(2) (IQR: 25.2-34.1), 75.4% had peripheral neuropathy and the median postcode score for socioeconomic status was 996 (IQR: 897-1022). Diabetic foot ulcer characteristics were: median cross sectional area of 1.5 cm(2) (IQR: 0.5-7.0), median volume of 0.4 cm(3) (IQR: 0.11-3.0), 45.1% on the plantar aspect of the foot, 16.6% UT Wound Grade of 0C to 3C (with ischaemia) and 11.8% with a Grade 0D to 3D (with infection and ischaemia) and 25.6% with osteomyelitis. Five patients required an amputation: 1 major and 4 minor amputations.

CONCLUSIONS

In accordance with other international studies, foot ulcers are more likely to present on the plantar surface of the foot and largely affect overweight older males with a long standing history diabetes in our outpatient hospital in Western Sydney.

Diabetes foot disease: the Cinderella of Australian diabetes management?

Diabetes is one of the greatest public health challenges to face Australia. It is already Australia's leading cause of kidney failure, blindness (in those under 60 years) and lower limb amputation, and causes significant cardiovascular disease. Australia's diabetes amputation rate is one of the worst in the developed world, and appears to have significantly increased in the last decade, whereas some other diabetes complication rates appear to have decreased. This paper aims to compare the national burden of disease for the four major diabetes-related complications and the availability of government funding to combat these complications, in order to determine where diabetes foot disease ranks in Australia. Our review of relevant national literature indicates foot disease ranks second overall in burden of disease and last in evidenced-based government funding to combat these diabetes complications. This suggests public funding to address foot disease in Australia is disproportionately low when compared to funding dedicated to other diabetes complications. There is ample evidence that appropriate government funding of evidence-based care improves all diabetes complication outcomes and reduces overall costs. Numerous diverse Australian peak bodies have now recommended similar diabetes foot evidence-based strategies that have reduced diabetes amputation rates and associated costs in other developed nations. It would seem intuitive that "it's time" to fund these evidence-based strategies for diabetes foot disease in Australia as well.

Toe and flow: essential components and structure of the amputation prevention team

At the end of an anatomic peninsula, the foot in diabetes is prone to acute and chronic complications involving neuropathy, vasculopathy, and infection. Effective management requires an interdisciplinary effort focusing on this triad. In this article, we describe the key factors leading to foot complications and the critical skill sets required to assemble a team to care for them. Although specific attention is given to a conjoined model involving podiatry and vascular surgery, the "toe and flow" model, we further outline three separate models of care--basic, intermediate, and center of excellence--that can be implemented in the developed and developing world.

Co-morbidity and the utilization of health care for Australian veterans with diabetes

OBJECTIVE

To examine the impact of co-morbidity on health service utilization by Australian veterans with diabetes.

METHODS

A retrospective cohort study was undertaken including veterans aged >or= 65 years dispensed medicines for diabetes in 2006. Data were sourced from the Australian Department of Veterans' Affairs health claims database. Utilization of preventive health services for diabetes was assessed, including claims for glycated haemoglobin (HbA(1c)) test, microabuminuria, podiatry services, diabetes care plans, medication reviews, case conferences, general practitioner (GP) management plans and ophthalmology/optometry services.

RESULTS

Among the 17,095 veterans dispensed medicines for diabetes, more than 80% had four or more co-morbid conditions. Those with a higher number of co-morbidities were more likely to have had claims for optometry/ophthalmology services and podiatry services, but not for other services. Veterans with at least one diabetes-related hospital admission had no more claims for diabetes health services than those who had no diabetics-related hospital admission, except for endocrinology services (relative risk = 1.26, 95% confidence intervals 1.15-1.37). Veterans with dementia were less likely to have had claims for diabetes health services while patients with renal failure were more likely to have had claims for the services.

CONCLUSIONS

Low utilization of preventive diabetes care services is apparent in all co-morbidity groups. Patients with renal failure or dementia used more and less health services resources, respectively. Given the high mean age of this population, there may be valid reasons for the low use, such as competing health demands and patients' preferences.

Foot problems and effectiveness of foot care education in children and adolescents with diabetes mellitus

OBJECTIVES

To assess foot care in paediatric and adolescent patients with diabetes mellitus and to evaluate the effectiveness of foot care education given to participants.

RESEARCH DESIGN AND METHODS

An 8-month prospective study of foot care in children and adolescents with type 1 and type 2 diabetes mellitus who attended diabetes clinics at the Royal Children's Hospital, Melbourne, where foot examination was performed at baseline and at follow-up. Patients and parents were given oral and written advice regarding foot care.

RESULTS

Five hundred and fifty-seven patients were examined at baseline, and 312 patients were reviewed at follow-up 3-6 months later. The majority of foot problems found at first assessment were potentially modifiable disorders of skin and nails (68.8%). The remainder (31.2%) were structural musculoskeletal disorders requiring referral to a podiatrist/orthotist. A total of 532 foot problems were recorded at baseline in a cohort of 557 patients and 161 foot problems at follow-up of 312 patients. Significant reduction of modifiable foot problems was seen at follow-up, particularly in those with longer duration of diabetes and in those whose body mass index was higher.

CONCLUSIONS

This study highlights the importance of foot examination and foot care advice for children and adolescents with diabetes. Larger prospective studies are required to establish prevalence and to optimize preventive interventions.

The mechanism of action of the vacuum-assisted closure device

BACKGROUND

The vacuum-assisted closure device is widely used clinically, yet its mechanisms of action are incompletely understood. In this study, the authors designed a partially splinted full-thickness murine vacuum-assisted closure model to better understand the mechanism of action of the vacuum-assisted closure device.

METHODS

Full-thickness wounds (n = 10 per group) were excised in diabetic mice and treated with the vacuum-assisted closure device or its isolated components: an occlusive dressing, subatmospheric pressure at 125 mmHg (suction), and a polyurethane foam without and with downward compression. Results were quantified with a two-dimensional immunohistochemical staging system based on blood vessel density (CD31) and cell proliferation (Ki67) 7 days after wounding. Microscopic strain was measured by fixing in situ all dressing modalities.

RESULTS

Wounds exposed to polyurethane foam in compressed and uncompressed dressings or to the vacuum-assisted closure device showed a 2-fold increase in vascularity compared with the occlusive dressing group (p < 0.05). The vacuum-assisted closure device in addition stimulated cell proliferation, with up to 82 percent Ki67-positive nuclei, compared with the other groups. Direct measurements of wound surface deformations showed significant microstrains in the vacuum-assisted closure and foam in compressed dressing groups (60 percent and 16 percent, respectively) compared with all other groups.

CONCLUSIONS

These data provide profound insights into the mechanism of action of the vacuum-assisted closure device, providing an explanation for the increases in wound bed vascularity and cell proliferation based on its components. Results suggest that the vascular response is related to the polyurethane foam, whereas tissue strains induced by the vacuum-assisted closure device stimulated cell proliferation.

Reduction in diabetic amputations over 11 years in a defined U.K. population: benefits of multidisciplinary team work and continuous prospective audit

OBJECTIVE

To assess changes in diabetic lower-extremity amputation rates in a defined relatively static population over an 11-year period following the introduction of a multidisciplinary foot team.

RESEARCH DESIGN AND METHODS

All diabetic patients with foot problems admitted to Ipswich Hospital, a large district general hospital, were identified by twice-weekly surveillance of all relevant in-patient areas and outcomes including amputations recorded.

RESULTS

The incidence of major amputations fell 62%, from 7.4 to 2.8 per 100,000 of the general population. Total amputation rates also decreased (40.3%) but to a lesser extent due to a small increase in minor amputations. Expressed as incidence per 10,000 people with diabetes, total amputations fell 70%, from 53.2 to 16.0, and major amputations fell 82%, from 36.4 to 6.7.

CONCLUSIONS

Significant reductions in total and major amputation rates occurred over the 11-year period following improvements in foot care services including multidisciplinary team work.

Emergency Management of Chronic Wounds

As America's emergency departments witness an increase in care provided to an aging population, the emergency physician increasingly evaluates and treats manifestations of chronic disease. Nonhealing wounds are often a presenting manifestation of chronic disease. They are a source of pain and disability for this population. Emergency physicians should possess a fundamental knowledge in the management of chronic wounds. This article familiarizes the emergency physician with the epidemiology of chronic wounds, the physiology of tissue repair, the pathophysiology involved in wound healing failure, the common types of chronic wounds, and specific management strategies.

Diabetic foot screening: why is it neglected?

Understanding reasons for the neglect of foot screening during the annual review of people with diabetes enables the development of solutions for this omission. This study explores the reasons within the context of health care delivery systems in terms of the professional, social, political and economic aspects of this screening. Information was obtained through reviewing publications on diabetic foot and health care reform. The omission of annual foot examination for people with diabetes is attributed to the nature of diabetes-related foot problems, people with diabetes, health care professionals and the current structure of health care delivery systems. Increasing the adherence to foot screening for those with diabetes requires short- and long-term strategies. Short- and long-term strategies for reminding patients and staff about foot screening are suggested.

Evidence-Based Protocol for Diabetic Foot Ulcers

BACKGROUND

Diabetic foot ulcers are the single biggest risk factor for nontraumatic foot amputations in persons with diabetes. Foot ulcers occur in 12 to 25 percent of persons with diabetes and precede 84 percent of all nontraumatic amputations in this growing population. Because of the high incidence of foot ulcers, amputations remain a source of morbidity and mortality in persons with diabetes. Strict adherence to evidence-based protocols as described herein will prevent the majority of these amputations.

METHODS

The collective experience of treating patients with neuropathic diabetic foot ulcers in four major diabetic foot programs in the United States and Europe was analyzed.

RESULTS

The following protocol was developed for patients with diabetic foot ulcers: (1) establishment of good communication among the patient, the wound healing team, and the primary medical doctor; (2) comprehensive, protocol-driven care of the entire patient, including hemoglobin A1c, microalbuminuria, and cholesterol as well as early treatment of retinopathy, nephropathy, and cardiac disease; (3) weekly objective measurement of the wound with digital photography, planimetry, and documentation of the wound-healing process using the Wound Electronic Medical Record, if available; (4) objective evaluation of blood flow in the lower extremities (e.g., noninvasive flow studies); (5) débridement of hyperkeratotic, infected, and nonviable tissue; (6) use of systemic antibiotics for deep infection, drainage, and cellulitis; (7) off-loading; (8) maintenance of a moist wound bed; (9) use of growth factor and/or cellular therapy if the wound is not healing after 3 weeks with this protocol; and (10) consideration of the use of vacuum-assisted therapy in complex wounds.

CONCLUSIONS

In diabetic foot ulcers, availability of the above modalities, in combination with early recognition and comprehensive treatment, ensures rapid healing, minimizes morbidity and mortality rates, and eliminates toe and limb amputations in the absence of ischemia and osteomyelitis.

Assessment and management of inpatients with acute diabetes-related foot complications: room for improvement

BACKGROUND

Australian data are currently lacking regarding management guidance, resource usage and outcomes of patients with diabetes requiring hospitalization for management of acute foot complications.

AIMS

The aims of the present study were to review hospital admissions for diabetes-related foot complications and current assessment and management of these complications, and to formulate recommendations for future models of care.

METHODS

A retrospective review of patient records from 1 July 1999 to 30 June 2000 was carried out. Recorded assessment, investigations, management, amputation rates, referral rates and length of hospital stay were reviewed.

RESULTS

There were 69 admission episodes in 12 months (total patients n = 50). The mean age was 64 years, with 44 male patients (64%) and 25 female patients (36%). The mean diabetes duration was 11 years (range <1-47 years). The majority of patients had type 2 diabetes. Assessment for known risk factors for ulceration and amputation was variable with history of previous ulcer/amputation recorded for 24 (35%) admissions, results of neurological assessment recorded for 11 (16%) and assessment of pedal pulses documented for 51 (74%). Glycated haemoglobin was performed during 35 (51%) admissions. Patients were admitted under one of 11 different inpatient units and the average interdepartmental referral rate was one referral per patient per admission. The average length of stay was 17 days, with total bed days occupied 1163 days. Minor amputation was performed in 25 (36%) cases and major amputation in 8 (11%).

CONCLUSIONS

Clinical assessment, investigation and management of this population are highly variable. This has a significant impact on the final clinical outcome, and changes to current processes are required to overcome the substantial burden of diabetic foot disease.

Diabetes care and complications in a remote primary health care setting

Prevalence of complications of type 2 diabetes in a remote Australian Indigenous community was measured as part of a population survey of risk factors for diabetes and cardiovascular disease. Information was obtained from history, clinical examination, blood sample and medical records. Forty-three diabetic participants (six newly diagnosed) were assessed from a sample of 339 (12% diabetes prevalence); mean age 50 (range 31-67), duration of diabetes 5.6 (0-15) years, 40% male. Risk factors/complications: 70% with >/= 25, 50% cigarette smokers, HbA1c 8.5 (S.D. 2.9)%, cholesterol 4.8 (0.8)mmol/l, triglycerides 2.7 (1.6)mmol/l, HDL 0.83 (0.2)mmol/l; 60% had albuminuria (micro 38%, macro 22%), 47% were hypertensive, 7% (n = 2) had retinopathy, 24% had peripheral neuropathy, none had peripheral vascular disease, 14% had documented coronary vascular and one participant cerebrovascular disease. Of 37 with previously diagnosed diabetes: 43% were on aspirin, 65% on metformin, 80% with albuminuria on ACE inhibitors. Four additional diabetic participants (not studied) were receiving renal dialysis elsewhere. The results demonstrate on the one hand, very high indices of cardiovascular risk (smoking, hypertension, dyslipidaemia and albuminuria) and on the other, good quality primary health care providing good detection and follow up management of type 2 diabetic patients.

Diabetes care in an Australian population: frequency of screening examinations for eye and foot complications of diabetes

OBJECTIVE

The aim of this work was to study the frequency of examining for diabetic eye and foot complications in an Australian population and to study factors associated with regular screening.

RESEARCH DESIGN AND METHODS

The Australian Diabetes, Obesity, and Lifestyle Study (AusDiab) was a population-based study of 11,247 people from randomly selected areas of Australia. Participants identified as having previously diagnosed diabetes (n=475) were invited to participate in the complications study. Measures included foot examination, retinopathy photography, and self-report use of health care services.

RESULTS

Seventy-seven percent of participants reported having an eye examination within the previous 2 years, and 50% reported having their feet examined by a health professional in the previous year. Type of diabetes treatment (odds ratio 1.46, 95% CI 0.85-2.50 for tablets versus diet alone and 4.17, 1.71-10.17 for insulin or insulin and tablets versus diet alone) and visiting a diabetes nurse educator in the previous 12 months (2.14, 1.18-3.87) were independent predictors of having had an eye examination. Duration of diabetes (1.33, 1.06-1.67 per year) and visiting a diabetes nurse educator in the previous 12 months (1.89, 1.20-2.95) were independent predictors of a foot examination.

CONCLUSIONS

This study has shown that retinopathy screening is performed more frequently than foot screening in Australia. This may be due to the implementation of eye screening programs and awareness campaigns. Foot screening appears to be poor, with less than one-half of the population reporting a regular examination for foot complications. In Australia, diabetes nurse educators play a key role in promoting screening for diabetes complications.

Trends in diabetes management practices of patients from an Australian insulin-treated diabetes register

AIMS

To compare diabetes management practices in 2001 among individuals from Tasmania, Australia, with a previous management survey conducted in 1995-7.

METHODS

Subjects were ascertained through the Tasmanian Insulin-Treated Diabetes Register. General demographic data were collected by telephone interview, and participants mailed a questionnaire on their diabetes management practices.

RESULTS

The response rate in 2001 was 80.8% (n=1336). There was a trend to more frequent blood glucose self-monitoring, notably in those less than 25 years (P<0.001 for monitoring >2 times/day), together with continued uptake of the pen system of insulin administration. More intensive shared management by general practitioner and diabetes specialist was noted, including a greater proportion visiting their doctor more than five times per year (P=0.006 for those <50 years). Most patients continue to be appropriately screened for hypertension and retinopathy. Dietitian visits declined overall (P=0.03 for at least annual visits), and there appeared to be an inadequate level of foot examination by patients and doctors.

CONCLUSIONS

The survey indicated that most patients were taking greater responsibility for their metabolic control, and intensive management practices and more convenient methods of administration may be contributors. Two areas of possible concern are access to dietitian services, and patient and health provider education on appropriate foot care.

Risks to feet in the top end: outcomes of diabetic foot complications

BACKGROUND

The foot complications of diabetes are severe, disabling, costly and common in the Northern Territory. An understanding of the pathogenesis, the disease spectrum and treatment efficacy, however, is poor. The patterns of disease are documented in the present study; factors associated with good and poor outcomes are identified; and improved management strategies are proposed.

METHODS

All patients presenting to the High Risk Foot Service at Royal Darwin Hospital between March 1997 and March 2000 were included in the present study, and details regarding the status of their feet, their demographics, their treatment and their outcomes were recorded prospectively. Logistic regression analysis was undertaken to determine associations between factors of interest and outcomes of healing and amputation.

RESULTS

One hundred and twenty-six patients were recorded, 41% of whom had neuropathic ulcers and 63% of whom had severe disease at presentation. Two types of diabetic foot pathology were recognized that are not usually classified: acute injury without neuropathy (10%) and deep soft tissue infection alone (9%).Thirty-seven percent and 23% of patients required minor and major amputations, respectively. The total number of hospital bed-days was 5813. Total contact casting was associated with good healing rates in 16 patients. Major amputation was associated with ischaemia, severe disease at presentation and increasing age.

CONCLUSIONS

Patterns of diabetic foot disease which are not commonly recognized are described in the present study; the severity and cost of the problem are documented; and some factors which lead to poor outcome, such as late presentation, are identified. Attention should be paid, through a multidisciplinary team, to timely referral from primary care, patient education, total contact casts and appropriate revascularization.