The efficacy of maggot debridement therapy--a review of comparative clinical trials

Use of biosurgery for the treatment of foot ulcers infected with therapy-resistant bacteria: a case report

Biosurgery (larval therapy) has been used for centuries. However, in recent times, this treatment has been replaced with the use of antibiotics for the treatment of wounds. Due to increasing antibiotic resistance, larval therapy is once again coming to the fore as an effective and efficient treatment. Due to the increasing ageing population, along with an increase in patients with arterial occlusive disease, diabetes and immobility, the number of patients with hard-to-heal wounds will increase. The stressors associated with wounds, such as pain, limited physical functionality, depression and social withdrawal, have a negative impact on patient quality of life. This case report documents the performance of biosurgery in a patient with multimorbidities.

Pain Assessment in Patients Undergoing Maggot Debridement Therapy in the Process of Local Treatment of Chronic Wounds

(1) Background: Developing and implementing strategies for local wound care focused on improving the quality of life related to health status and reducing treatment costs for this patient group poses a challenge to contemporary healthcare systems. The utilization of Maggot Debridement Therapy (MDT) is one potential form of local therapy for preparing wounds for the healing process. The debridement of the wound bed with medical maggots is highly precise, and the defensins produced by the larvae eliminate bacteria and stimulate tissue regeneration. However, the presence of larvae in the wound may lead to the occurrence of pain symptoms. The aim of the study was to assess the intensity of pain during larval therapy in patients with chronic wounds treated in outpatient settings. (2) Patients and Methods: The study employed a diagnostic survey and estimation; the tool consisted of a research protocol comprising three parts (questionnaires). Inclusion criteria for the study were voluntary consent to participate (completion of the MDT acceptance questionnaire), chronic wounds of vascular etiology or pressure injuries, full-thickness skin or deep tissue damage, and pain intensity not exceeding four on the NRS (Numerical Rating Scale: 0-no pain, 10-the most severe pain) at the time of the study. Patient observation during the 3-day treatment was conducted by a wound care clinic nurse, assessing pain intensity once every 24 h during the larval dressing changes. (3) Results: Out of 348 individuals who qualified for MDT during the study period, 215 individuals participated in the study: 94 women (43.7%) and 121 men (56.3%). The age of the participants ranged from 28 to 97 years (mean 69.87 ± 12.95). Each participant experienced mild pain (2.26 ± 1.60 on the NRS) on the day of qualification for the study. An increase in pain intensity, according to subjective assessments, was reported by 29.3% of participants (n = 63). On the third day of MDT therapy, an increase in pain intensity was observed, reaching a mean value of 4.79 ± 2.12 (p < 0.0001). Participants with pressure injuries showed the lowest pain intensity, which increased in consecutive days for all types of wounds. Additionally, the increase in pain intensity in patients with vascular etiology wounds was greater compared to patients with pressure injuries (p < 0.001). (4) Conclusions: Local wound therapy with Lucilia sericata larvae increases pain intensity in the consecutive days of treatment. The wound area and the time since its occurrence may determine pain symptoms.

Larval Wound Therapy: Possibilities and Potential Limitations-A Literature Review

Patient-centered care (PCC) is recognized as a standard in healthcare for determining high quality. Honoring patients' values, experiences, needs, and preferences in devising, coordinating, and delivering care underscores the enhancement of the therapeutic rapport between patients and healthcare providers. Wound treatment involves a multi-stage process encompassing diagnostics and local wound dressing, which reduces the risk of infection through a coordinated interdisciplinary team. Within this team, nurses undertake specific professional functions and roles. The implementation of local therapy using innovative and scientifically substantiated methods may be hindered by a deficit of knowledge or inappropriate knowledge among staff and patients themselves. This study presents the challenges concerning the care of patients with chronic wounds treated using Lucilia sericata larvae, based on a review of the current scientific literature. A critical analysis of the literature spanning from 2002 to 2022 was conducted using the Medline, PubMed, Cochrane, and Termedia databases, employing keywords such as "maggot debridement therapy" in relation to acceptance and perception. As a result of the preliminary selection, 472 papers were identified, of which 12 publications were included in the development of this concept. The acquired data were organized and presented in the concluding section in the form of tables, accompanied by descriptions and references to individual studies. Negative psychological and somatic sensations were among the most prominent challenges among patients treated with Maggot Debridement Therapy (MDT). Pain related to peripheral ischemia or infection in this group of patients requires pain prophylaxis, including hyperalgesia and allodynia, in order to improve method tolerance. On the other hand, augmenting patients' understanding of MDT diminishes negative emotions, reinforces positive behaviors, and mitigates anxiety levels. MDT constitutes an effective and safe method. Its widespread use for chronic wounds requires substantial knowledge among healthcare professionals and patient education, along with that of their caregivers, to develop a positive attitude.

Flesh Fly Maggot-Infected Abscess in a Burn Victim Patient in the United States Without a History of International Travel: A Case Report

This case report describes an uncommon occurrence of myiasis, specifically a maggot-infected abscess, in a patient with reduced skin sensitivity resulting from severe burns. Myiasis is the infestation of live animal tissue by fly larvae, and while it is primarily associated with tropical and subtropical regions, cases acquired within the United States are rare. The presented case involves a 70-year-old male who arrived at the emergency department with an intensely painful, non-healing wound in the left elbow. Upon examination, the wound was found to be infested with numerous live maggots, and subsequent investigations revealed the larvae to be of the flesh fly species (Sarcophagidae). The patient's history of reduced skin sensitivity, previous burn injuries, and exposure to outdoor environments, coupled with poor hygiene and homelessness, likely contributed to the infestation. This report emphasizes the importance of considering myiasis caused by flesh fly larvae even in non-travel-related cases within the United States. Early recognition and prompt treatment are vital to preventing complications and secondary infections. Healthcare providers should remain vigilant in identifying and managing myiasis, and patients with decreased skin sensation should be educated about the need for regular skin surveillance and the utilization of preventive measures to mitigate potential infestations.

Larval Therapy for Treatment of Chronic Wounds Colonized by Multi-resistant Pathogens in a Pediatric Patient: A Case Study

BACKGROUND

Chronic wounds are susceptible to colonization with gram-positive and gram-negative bacteria that may be resistant to antimicrobial dressings and systemic antibiotics. In January 2004, the US Food and Drugs Administration approved use of medicinal larvae for use in humans and animals for resistant organisms. Despite use in adults, there is a paucity of evidence evaluating its efficacy and safety in the pediatric population.

CASE

T was a 5-year-old boy with several chronic wounds infected with multidrug-resistant Pseudomonas aeruginosa. The wounds were originally treated with chemical debridement, dressings containing ionic silver, negative-pressure wound therapy (NPWT), and antibiotics without success. Consequently, a multidisciplinary team implemented maggot debridement therapy (MDT).

CONCLUSIONS

After MDT, one wound completely epithelialized and the other wounds achieved a reduction in size with 70% epithelization. Therapy also led to a reduction in wound odor, exudate, and pain. The other wounds were closed after additional management with dressing containing nanocrystalline silver and NPWT.

Therapeutic effects of Lucilia sericata larval excretion/secretion products on Leishmania major under in vitro and in vivo conditions

BACKGROUND

Leishmaniasis is a neglected infectious disease caused by protozoa of the genus Leishmania. The disease generally manifests as characteristic skin lesions which require lengthy treatment with antimonial drugs that are often associated with adverse side effects. Therefore, a number of studies have focused on natural compounds as promising drugs for its treatment. This study aimed to evaluate the effects of larval excretion/secretion products (ES) of Lucilia sericata in crude and fractionated forms on Leishmania major, by using in vitro and in vivo models.

METHODS

The in vitro experiments involved evaluation of ES on both promastigotes and macrophage-engulfed amastigotes, whereas the in vivo experiments included comparative treatments of skin lesions in L. major-infected mice with Eucerin-formulated ES and Glucantime.

RESULTS

The half maximal inhibitory concentrations of the crude ES, > 10-kDa ES fraction, < 10-kDa ES fraction, and Glucantime were 38.7 μg/ml, 47.6 μg/ml, 63.3 μg/ml, and 29.1 μg/ml, respectively. Significant differences were observed between percentage viabilities of promastigotes treated with the crude ES and its fractions compared with the negative control (P < 0.0001). The crude ES was more effective on amastigotes than the two ES fractions at 300 μg/ml. The macroscopic measurements revealed that the reduction of lesion size in mice treated with the crude ES followed quicker cascades of healing than that of mice treated with Glucantime and the ES fractions.

CONCLUSIONS

The present study showed that the larval ES of L. sericata in both crude and fractionated forms are effective for both intracellular and extracellular forms of L. major. Also, the ES exert both topical and systemic effects on mice experimentally infected with L. major.

Health professionals' perceptions of maggot debridement therapy

BACKGROUND

Maggot debridement therapy (MDT), or the use of maggots in dead tissue removal, has been shown to be beneficial in wound healing. Yet MDT in the US is often only used once conventional debridement methods have failed.

METHOD

In this study, nine health professionals, experienced in MDT, were interviewed in order to identify and analyse the perceived societal barriers to MDT acceptance and usage in the US.

RESULTS

Through qualitative analysis, using the grounded theory framework, this study found that among those interviewed, insurance reimbursement restrictions and stigmatisation of medicinal maggots were the factors driving resistance to MDT use.

CONCLUSION

Specifically, the 'yuck' factor and the perception of MDT as an 'ancient' modality contributed towards MDT stigma; in addition, lack of outpatient insurance coverage deterred MDT use. These findings provide useful information regarding the perceptual and systemic barriers that prevent greater acceptance of MDT. Ultimately, these barriers must be understood if we are to facilitate MDT implementation and improve MDT usage in the future.

What is the effect of larval therapy on the debridement of venous leg ulcers? A systematic review

AIM

To determine the impact of larval therapy on the debridement of venous leg ulcers, in comparison to other debridement methods or no debridement.

METHOD

Using systematic review methodology, published quantitative studies focusing on the effect of larval therapy on the debridement of venous leg ulcers were included. The search was conducted in January 2020 and updated in May 2021 using CINAHL, PubMed, Embase, and the Cochrane library, and returned 357 records, of which six studies met the inclusion criteria. Data were extracted using a predesigned extraction tool and all studies were quality appraised using the RevMan risk of bias assessment tool.

RESULTS

Larval therapy was found to debride at a faster rate than hydrogel (p = 0.011, p < 0.001, p = 0.0039), have a similar effect to sharp debridement (p = 0.12, p = 0.62), and was a resource-effective method of debridement (p < 0.05, p < 0.001, p < 0.001). When larval therapy in combination with compression therapy was compared to compression alone, larvae had a greater effect on debridement (p < 0.05), however, it did not improve overall wound healing rates (p = 0.54, p = 0.664, p = 0.02). Pain levels increased during larval therapy and reduced after treatment, when compared to other standard debridement techniques.

CONCLUSION

Larval therapy promotes rapid debridement of venous leg ulcers. However, further high quality randomised controlled trials, comparing larval therapy to other debridement methods for venous leg ulcers, incorporating the use of compression is required to determine the long term effects of larval therapy.

Changing attitudes toward maggot debridement therapy in wound treatment: a review and discussion

Maggot debridement therapy is the real-time placement of maggots into a wound by health professionals for the treatment of diabetic ulcers or hard-to-heal wounds infected with antibiotic-resistant bacteria. Maggot debridement therapy shortens healing and disinfects wounds. This paper is a literature review of maggot debridement therapy in the clinical setting today and addresses the costs and benefits of this therapy. It includes recommendations to engage healthcare providers and increase awareness of this therapeutic treatment. A case study is presented on the use of maggot therapy for full debridement of a necrotic wound and clearing of a meticillin-resistant Staphylococcus aureus infection. There is also discussion on how to engage healthcare workers and reduce anxieties about the use of maggots as a treatment for hard-to-heal wounds. Education and awareness are the key factors in changing healthcare workers attitudes to maggot debridement therapy.

Advantages of Maggot Debridement Therapy for Chronic Wounds: A Bibliographic Review

GENERAL PURPOSE

To present an overview of the advantages of maggot debridement therapy as a treatment for chronic wounds through the review of several larval properties.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will be able to:1. Summarize the use, process, and precautions for maggot debridement to treat chronic wounds.2. Synthesize the results of the bibliographic review of the use of maggot debridement to treat chronic wounds.

ABSTRACT

Maggot debridement therapy (MDT) is effective for ulcer debridement, achieving it in less time than other therapies. It offers a benefit to healing. However, it is unclear whether maggots reduce treatment time and there is considerable controversy around the treatment's potential antimicrobial action and cost-effectiveness. Nevertheless, it can be effective in preventing amputations and reducing the need for systemic antibiotics. This bibliographic review assesses the advantages of MDT as a treatment for chronic wounds through the review of several larval properties. The review was carried out by consulting biomedical databases including CINAHL, MEDLINE (PubMed), and Scopus, and concludes that MDT is an effective debridement and potential technique to facilitate healing. However, more data is needed on the wound type application frequency and the efficacy of treatment.

Use of maggot debridement therapy in hospitalised patients in Germany

Exact data regarding the clinical role of maggot debridement therapy (MDT) for wound care in a specific country are not available. Thus, we analysed the use of MDT in hospitalised patients in Germany. Detailed lists of all hospitalised cases treated with MDT in Germany for the years 2011 to 2016 were provided by the Federal Statistical Office as well as the lists of the 15 most frequent principal and additional diagnoses, respectively, and the 10 most frequent procedures documented with MDT in 2016. Within the 6-year time period of the study, the number of cases treated with MDT increased by 11% from 4513 in 2011 to 5.017 in 2016. Lower leg and foot were the most frequent anatomic sides of treatment counting up to 83.9% of all cases. In addition, MDT procedures for temporary soft tissue coverage including negative pressure wound therapy were often performed: for treatment of large areas in 36.7% and small areas in 6.2%. 41.3% of all cases treated with MDT had infection with Escherichia coli and 35.9% of all cases with Bacillus fragilis. Our analysis shows a limited use of MDT with a small increase only in the last 6 years in German hospitals. MDT is predominately used to treat foot or leg ulcers.

What is the optimal treatment time for larval therapy? A study on incubation time and tissue debridement by bagged maggots of the greenbottle fly, Lucilia sericata

The effective use of larvae of the greenbottle fly, Lucilia sericata, in wound debridement requires a working knowledge of how feeding changes over time. Using a laboratory assay and bagged larval dressings, the effect of incubation time on larval feeding rates and body mass was investigated for up to 120 hours at 32°C. The mass of tissue digested increased significantly in incremental 24-hour periods up to 72 hours, with no significant consumption occurring afterwards. Larval mass increased only up to 48 hours. A further test comparing the efficacy of a single 96-hour application of larvae against two consecutive 48-hour applications found that the mass of tissue digested in the latter was 14.3% higher than the former, a difference that was statistically significant. Current clinical guidance suggests a 4-day application period for bagged larvae. Based on these results, an incubation time of 72 hours (3 days) for bagged larvae would be the most effective at the study temperature. However, it is acknowledged that wound temperature can vary, whereby feeding rates would likely differ. In view of this, we conclude that a period of 3 to 4 days is optimum for the application of larvae, and current guidelines should be adhered to.

Maggot debridement therapy with a direct dressing can cause compression injuries in patients with chronic limb ischemia

While there are no reports regarding dressing-associated iatrogenic skin ulcer as an adverse event of maggot debridement therapy (MDT), MDT is clinically used on patients with critical limb ischaemia with dermal fragility. Herein we report causes and counter measures for a case of iatrogenic skin ulcer induced by MDT dressing.

Wound Infections in Critical Care

Patients admitted to critical care units are at high risk for increased morbidity and mortality from skin and deep wound infections. Despite considerable progress, wound healing remains a challenge to many clinicians. Nurses working in critical care environments need to understand the anatomic and physiologic basis for wound healing, distinguish wound inflammation from wound infection, recognize the presence of biofilms, and implement evidence-based wound care in order to promote successful outcomes in this patient population.

The effect of Lucilia sericata- and Sarconesiopsis magellanica-derived larval therapy on Leishmania panamensis

This study's main objective was to evaluate the action of larval therapy derived from Lucilia sericata and Sarconesiopsis magellanica (blowflies) regarding Leishmania panamensis using an in vivo model. Eighteen golden hamsters (Mesocricetus auratus) were used; they were divided into 6 groups. The first three groups consisted of 4 animals each; these, in turn, were internally distributed into subgroups consisting of 2 hamsters to be used separately in treatments derived from each blowfly species. Group 1 was used in treating leishmanial lesions with larval therapy (LT), whilst the other two groups were used for evaluating the used of larval excretions and secretions (ES) after the ulcers had formed (group 2) and before they appeared (group 3). The three remaining groups (4, 5 and 6), consisting of two animals, were used as controls in the experiments. Biopsies were taken for histopathological and molecular analysis before, during and after the treatments; biopsies and smears were taken for assessing parasite presence and bacterial co-infection. LT and larval ES proved effective in treating the ulcers caused by the parasite. There were no statistically significant differences between the blowfly species regarding the ulcer cicatrisation parameters. There were granulomas in samples taken from lesions at the end of the treatments. The antibacterial action of larval treatment regarding co-infection in lesions caused by the parasite was also verified. These results potentially validate effective LT treatment against cutaneous leishmaniasis aimed at using it with humans in the future.

Towards next generation maggot debridement therapy: transgenic Lucilia sericata larvae that produce and secrete a human growth factor

BACKGROUND

Diabetes and its concurrent complications impact a significant proportion of the population of the US and create a large financial burden on the American health care system. FDA-approved maggot debridement therapy (MDT), the application of sterile laboratory-reared Lucilia sericata (green bottle fly) larvae to wounds, is a cost-effective and successful treatment for diabetic foot ulcers and other medical conditions. Human platelet derived growth factor-BB (PDGF-BB) is a secreted dimeric peptide growth factor that binds the PDGF receptor. PDGF-BB stimulates cell proliferation and survival, promotes wound healing, and has been investigated as a possible topical treatment for non-healing wounds. Genetic engineering has allowed for expression and secretion of human growth factors and other proteins in transgenic insects. Here, we present a novel concept in MDT technology that combines the established benefits of MDT with the power of genetic engineering to promote healing. The focus of this study is to create and characterize strains of transgenic L. sericata that express and secrete PDGF-BB at detectable levels in adult hemolymph, whole larval lysate, and maggot excretions/ secretions (ES), with potential for clinical utility in wound healing.

RESULTS

We have engineered and confirmed transgene insertion in several strains of L. sericata that express human PDGF-BB. Using a heat-inducible promoter to control the pdgf-b gene, pdgf-b mRNA was detected via semi-quantitative PCR upon heat shock. PDGF-BB protein was also detectable in larval lysates and adult hemolymph but not larval ES. An alternative, tetracycline-repressible pdgf-b system mediated expression of pdgf-b mRNA when maggots were raised on diet that lacked tetracycline. Further, PDGF-BB protein was readily detected in whole larval lysate as well as larval ES.

CONCLUSIONS

Here we show robust, inducible expression and production of human PDGF-BB protein from two conditional expression systems in transgenic L. sericata larvae. The tetracycline-repressible system appears to be the most promising as PDGF-BB protein was detectable in larval ES following induction. Our system could potentially be used to deliver a variety of growth factors and anti-microbial peptides to the wound environment with the aim of enhancing wound healing, thereby improving patient outcome in a cost-effective manner.

Safety, effectiveness and economic aspects of maggot debridement therapy for wound healing

BACKGROUND

Maggot therapy has recently attracted considerable attention as an emerging debridement technique for wound healing. This study aimed to review the safety, effectiveness and economic evaluations of Maggot Debridement Therapy for wound healing.

METHODS

To retrieve the relevant evidences, the Cochrane Library (until September 2014) was searched by appropriate keywords, using free text and Mesh. Systematic reviews, HTA reports and economic evaluation studies that compared larval therapy with other debridement therapies, such as hydrogel in patients with various kinds of ulcers in terms of side effects, the wound healing rate, the healing time, and cost per QALY, were included.

RESULTS

Five studies met the inclusion criteria which showed that healing with larval therapy happened a little earlier than the usual methods and that pain perception in larval therapy was a little more than usual methods (as by anesthetic conventional methods). However, the quality of life of those patients who received larval therapy was better and they showed a greater tendency to larval therapy as it was relatively safe and had a low rate of side effects.

CONCLUSION

It seems that larval therapy has several advantages such as rapid wound debridement, infection elimination, pain control and ulcer healing. The use of larval therapy has the potential to reduce side effects and decrease the need for amputation.

Seeking effective interventions to treat complex wounds: an overview of systematic reviews

BACKGROUND

Numerous, often multi-faceted regimens are available for treating complex wounds, yet the evidence of these interventions is recondite across the literature. We aimed to identify effective interventions to treat complex wounds through an overview of systematic reviews.

METHODS

MEDLINE (OVID interface, 1946 until October 26, 2012), EMBASE (OVID interface, 1947 until October 26, 2012), and the Cochrane Database of Systematic Reviews (Issue 10 of 12, 2012) were searched on October 26, 2012. Systematic reviews that examined adults receiving care for their complex wounds were included. Two reviewers independently screened the literature, abstracted data, and assessed study quality using the Assessment of Multiple Systematic Reviews (AMSTAR) tool.

RESULTS

Overall, 99 systematic reviews were included after screening 6,200 titles and abstracts and 422 full-texts; 54 were systematic reviews with a meta-analysis (including data on over 54,000 patients) and 45 were systematic reviews without a meta-analysis. Overall, 44% of included reviews were rated as being of high quality (AMSTAR score ≥ 8). Based on data from systematic reviews including a meta-analysis with an AMSTAR score ≥ 8, promising interventions for complex wounds were identified. These included bandages or stockings (multi-layer, high compression) and wound cleansing for venous leg ulcers; four-layer bandages for mixed arterial/venous leg ulcers; biologics, ultrasound, and hydrogel dressings for diabetic leg/foot ulcers; hydrocolloid dressings, electrotherapy, air-fluidized beds, and alternate foam mattresses for pressure ulcers; and silver dressings and ultrasound for unspecified mixed complex wounds. For surgical wound infections, topical negative pressure and vacuum-assisted closure were promising interventions, but this was based on evidence from moderate to low quality systematic reviews.

CONCLUSIONS

Numerous interventions can be utilized for patients with varying types of complex wounds, yet few treatments were consistently effective across all outcomes throughout the literature. Clinicians and patients can use our results to tailor effective treatment according to type of complex wound. Network meta-analysis will be of benefit to decision-makers, as it will permit multiple treatment comparisons and ranking of the effectiveness of all interventions. Please see related article: http://dx.doi.org/10.1186/s12916-015-0326-3.

Evaluating the effect of Sarconesiopsis magellanica (Diptera: Calliphoridae) larvae-derived haemolymph and fat body extracts on chronic wounds in diabetic rabbits

We evaluated extracts taken from S. magellanica third instar larvae fat body and haemolymph using a diabetic rabbit model and compared this to the effect obtained with the same substances taken from Lucilia sericata larvae. Alloxan (a toxic glucose analogue) was used to induce experimental diabetes in twelve rabbits. Dorsal wounds were made in each animal and they were infected with Staphylococcus aureus and Pseudomonas aeruginosa. They were then treated with haemolymph and lyophilized extracts taken from the selected blowflies' larvae fat bodies. Each wound was then evaluated by using rating scales and histological analysis. More favourable scores were recorded on the PUSH and WBS scales for the wounds treated with fat body derived from the larvae of both species compared to that obtained with haemolymph; however, wounds treated with the substances taken from S. magellanica had better evolution. Histological analysis revealed that treatment led to tissue proliferation and more effective neovascularisation in less time with both species' fat body extracts compared to treatment with just haemolymph. The results suggest the effectiveness of the substances evaluated and validate them in the animal model being used here as topical agents in treating chronic wounds.

The effects of Sarconesiopsis magellanica larvae (Diptera: Calliphoridae) excretions and secretions on fibroblasts

Sarconesiopsis magellanica is a necrophagous blowfly which is relevant in both forensic and medical sciences. Previous studies regarding this species have led to understanding life-cycle, population and reproduction parameters, as well as identifying and characterising proteolytic enzymes derived from larval excretions and secretions (ES). As other studies have shown that ES proteolytic activity plays a significant role in wound healing and fibroblasts play a relevant role in granulation tissue formation during such healing, the present study was aimed at analysing the biological effect of S. magellanica larval ES on fibroblasts. ES were obtained from third-instar larvae and added to fibroblast cells at three concentrations (10, 5 and 1 μg/mL) to evaluate their behaviour. MTT assays were used for analysing cell proliferation and viability, whilst cell adhesion was measured by optical density with 10% SDS. Fibroblast migration and morphology was recorded by microscopic observation. ES did not affect fibroblast viability and induced an increase in cell proliferation; cell adhesion became reduced, whilst cell migration through extracellular matrix increased. ES also induced a decreased cell surface and morphological alterations. Changes in all the above-mentioned parameters were reduced when ES were incubated at 60 °C, probably due to protease denaturation. These results suggested that the proteases contained in S. magellanica larval ES contributed towards granulation tissue formation, increased cell migration and promoted cell proliferation. All these data support carrying out further experiments aimed at validating S. magellanica usefulness in larval therapy.

Midgut lysozymes of Lucilia sericata - new antimicrobials involved in maggot debridement therapy

Larvae of Lucilia sericata are used for maggot debridement therapy (MDT) because of their ability to remove necrotic tissue and eradicate bacterial pathogens of infected wounds. So far, very few antibacterial factors have been fully characterized (eg lucifensin). Using a molecular approach, some other putative antimicrobial compounds, including three novel lysozymes, have been previously identified and predicted to be involved in MDT. Nevertheless, data on lysozymes tissue origin and their functions have never been elucidated. Therefore, the aim of this study was to investigate the expression of three lysozymes in L. sericata and confirm their antibacterial effects within MDT. Moreover, we characterized the eradication process of bacteria within the digestive system of maggots and determined the role of lysozymes in this process. We found that three lysozymes are expressed in specific sections of the L. sericata midgut. Recombinant lysozymes displayed comparable antibacterial activity against Micrococcus luteus. Furthermore, the majority of Gram-positive bacteria were destroyed in vivo within the particular section of the L. sericata midgut where lysozymes are produced. Larval ingestion and subsequent eradication of wound pathogens during their passage through the intestine of maggots are due to, at least in part, antibacterial action of three midgut lysozymes.

Maggot debridement therapy: a systematic review

Maggot debridement therapy is used extensively in the UK in both community and hospital situations, but remains a potentially under-used modality in many wound care markets. It promotes wound healing by performing three key processes: debridement, disinfection and growth-promoting activity. It can be used for the debridement of non-healing necrotic skin and soft tissue wounds, including pressure ulcers, venous stasis ulcers, neuropathic foot ulcers and non-healing traumatic of post-surgical wounds. With the increase in chronic diabetic foot wounds, maggot debridement therapy is a promising tool for health professionals dealing with difficult wounds. This article presents an overview of the research evidence surrounding maggot debridement therapy that serves as a guide to health professionals who may be users of this form of treatment now and in the future.

Maggot Therapy for Elephantiasis Nostras Verrucosa Reveals New Applications and New Complications: A Case Report

Elephantiasis nostras verrucosa (ENV) is a rare dermatologic condition caused by chronic nonfilarial lymphedema. The treatment for ENV is challenging and based solely on case reports. We report novel therapy for ENV with maggot debridement therapy (MDT), an effective wound therapy that has gained popularity with the rise of antimicrobial resistance. MDT, in combination with tangential surgical debridement, was effective in the treatment of ENV. In nature, sheep infested with more than 16 000 blow fly larvae exhibit ammonia toxicity. Although hyperammonemia as a side effect of maggot therapy has been theorized, its existence has not been described in human studies until this case. This patient exhibited hyperammonemia during maggot therapy; with alterations in serum ammonia reflecting changes in larval population. Maggot therapy should be considered for the treatment of ENV. Hyperammonemia with maggot therapy exists, and clinicians who employ this treatment should be aware of this potential adverse effect.

Recent advances in developing insect natural products as potential modern day medicines

Except for honey as food, and silk for clothing and pollination of plants, people give little thought to the benefits of insects in their lives. This overview briefly describes significant recent advances in developing insect natural products as potential new medicinal drugs. This is an exciting and rapidly expanding new field since insects are hugely variable and have utilised an enormous range of natural products to survive environmental perturbations for 100s of millions of years. There is thus a treasure chest of untapped resources waiting to be discovered. Insects products, such as silk and honey, have already been utilised for thousands of years, and extracts of insects have been produced for use in Folk Medicine around the world, but only with the development of modern molecular and biochemical techniques has it become feasible to manipulate and bioengineer insect natural products into modern medicines. Utilising knowledge gleaned from Insect Folk Medicines, this review describes modern research into bioengineering honey and venom from bees, silk, cantharidin, antimicrobial peptides, and maggot secretions and anticoagulants from blood-sucking insects into medicines. Problems and solutions encountered in these endeavours are described and indicate that the future is bright for new insect derived pharmaceuticals treatments and medicines.

High glucose improves healing of periodontal wound by inhibiting proliferation and osteogenetic differentiation of human PDL cells

Periodontal ligament (PDL) cells play an important role in wound healing of periodontal tissues. Response of PDL cells' cellular activity to high-glucose concentration levels may be the key in understanding the relationship between periodontal disease and diabetes mellitus. We studied the effect of high-glucose medium on proliferation of PDL cells in vitro. PDL cells were cultured for 1, 4, 7, 10, 14 and 17 days in normal (1100 mg/l) glucose or in high (4500 mg/l) glucose medium. The 3-(4,5-dimethylithiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay for proliferation was performed. In order to evaluate the osteogenetic differentiation of human PDL cells, the cells were induced with normal- or high-glucose medium for 1, 7, 14, 21 and 28 days. The results indicated that high glucose significantly inhibited proliferation of PDL cells. Concerning the mineralised nodule formation, the percentage of calcified area to total culture dish of PDL cells in high glucose level was lower than that in normal glucose medium. The increase in alkaline phosphatase activity and collagen expression could be observed in high-glucose-containing osteogenetic factor. In conclusion, high glucose improves healing of periodontal wound by inhibiting proliferation and differentiation of PDL cells, which could explain for delayed periodontal regeneration and healing in diabetic patients.

Growth and Survival of Bagged Lucilia sericata Maggots in Wounds of Patients Undergoing Maggot Debridement Therapy

Maggot debridement therapy (MDT) is an established method of debridement of nonhealing wounds. Despite intense clinical research about its efficacy and effects of substances produced by the larvae, growth and development of maggots in the wounds remain largely unexplored. In the present study, the bags with larvae (n = 52), which had been used to debride traumatic, ischemic, diabetic and venous ulcers, were collected and examined. Survival, length, width and larval instar of the maggots within each bag were recorded and analyzed with respect to the wound type and duration of the treatment. Survival of maggots after a 48-h cycle of MDT ranged between 63.6 and 82.7%. Maggots in venous ulcers had on average 9–19% higher mortality than maggots within traumatic, ischemic, and diabetic ulcers. Length of larvae after 48 h cycle of MDT reached on average 7.09–9.68 mm, and average width varied between 1.77 and 2.26 mm. Larvae in venous ulcers were significantly smaller after 48 h, but not after 72 h treatment compared to the other wound types. Further studies should be aimed to identify other patient-associated factors which might influence growth and survival of the larvae during maggot debridement therapy.