How do Maggots operate?: The Underlying Mechanisms of Action of Maggot Debridement Therapy

Bonjer, H.J. [Promotor]Schreurs, M.W.J. [Copromotor

TIME management by medicinal larvae

Wound bed preparation (WBP) is an integral part of the care programme for chronic wounds. The acronym TIME is used in the context of WBP and describes four barriers to healing in chronic wounds; namely, dead Tissue, Infection and inflammation, Moisture imbalance and a non-migrating Edge. Larval debridement therapy (LDT) stems from observations that larvae of the blowfly Lucilia sericata clean wounds of debris. Subsequent clinical studies have proven debriding efficacy, which is likely to occur as a result of enzymatically active alimentary products released by the insect. The antimicrobial, anti-inflammatory and wound healing activities of LDT have also been investigated, predominantly in a pre-clinical context. This review summarises the findings of investigations into the molecular mechanisms of LDT and places these in context with the clinical concept of WBP and TIME. It is clear from these findings that biotherapy with L. sericata conforms with TIME, through the enzymatic removal of dead tissue and its associated biofilm, coupled with the secretion of defined antimicrobial peptides. This biotherapeutic impact on the wound serves to reduce inflammation, with an associated capacity for an indirect effect on moisture imbalance. Furthermore, larval serine proteinases have the capacity to alter fibroblast behaviour in a manner conducive to the formation of granulation tissue

A randomized controlled trial of larval therapy for the debridement of leg ulcers: Results of a multicenter, randomized, controlled, open, observer blind, parallel group study

It has been known for centuries that the application of larvae is useful to heal certain wounds by facilitating debridement of necrotic tissue,1 yet the efficacy of larval therapy continues to be debatable. This study compared the clinical effectiveness of a larval therapy dressing (BioFOAM) with a standard debridement technique (Purilon gel; hydrogel) in terms of time to debridement of venous (VLU) or mixed arterial/venous (MLU) leg ulcers. Data analyses were conducted on 88 subjects. Sixty‐four subjects completed the full study. Of these, 31 of the 32 (96.9%) patients who completed treatment in the larvae arm debrided fully, compared with 11 of the 32 (34.4%) patients who completed the hydrogel arm. In addition, 42 (48%) ulcers fully debrided within the 21‐day intervention phase, 31 (67.4%) from the larvae arm (n = 46), and 11 (26.2%) from the hydrogel arm (n = 42), which was statistically significant (p = 0.001) in support of larvae. A statistically significant difference was also observed between treatment arms with regard to numbers of dressing changes during the intervention phase of the study (p < 0.001) in that subjects in the larvae arm required significantly fewer dressing changes(mean = 2.83) than those in the hydrogel arm (mean = 5.40). There were no statistically significant differences in the clinical condition of the wound bed and surrounding skin by intervention. Subjects in the larvae arm experienced more ulcer‐related pain or discomfort than subjects in the hydrogel arm (p < 0.001). This study provided good evidence to show that larval therapy, in the form of a BioFOAM dressing, debrided VLU and MLU considerably more quickly than a hydrogel, although the possibility of resloughing should be closely monitored

Maggot excretions and secretions reduce complement activation

Immunogenetics and cellular immunology of bacterial infectious disease