Morphine enhances tissue content of collagen and increases wound tensile strength

Assessment of the structural and functional characteristics of human mesenchymal stem cells associated with a prolonged exposure of morphine

The discovery of the expression of opioid receptors in the skin and their role in orchestrating the process of tissue repair gave rise to questions regarding the potential effects of clinical morphine treatment in wound healing. Although short term treatment was reported to improve tissue regeneration, in vivo chronic administration was associated to an impairment of the physiological healing process and systemic fibrosis. Human mesenchymal stem cells (hMSCs) play a fundamental role in tissue regeneration. In this regard, acute morphine exposition was recently reported to impact negatively on the functional characteristics of hMSCs, but little is currently known about its long-term effects. To determine how a prolonged treatment could impair their functional characteristics, we exposed hMSCs to increasing morphine concentrations respectively for nine and eighteen days, evaluating in particular the fibrogenic potential exerted by the long-term exposition. Our results showed a time dependent cell viability decline, and conditions compatible with a cellular senescent state. Ultrastructural and protein expression analysis were indicative of increased autophagy, suggesting a relation to a detoxification activity. In addition, the enhanced transcription observed for the genes involved in the synthesis and regulation of type I collagen suggested the possibility that a prolonged morphine treatment might exert its fibrotic potential risk, even involving the hMSCs.

Enhanced Skin Incisional Wound Healing With Intracellular ATP Delivery via Macrophage Proliferation and Direct Collagen Production

This study sought to use a newly developed intracellular ATP delivery to enhance incisional wound healing to reduce surgical wound dehiscence and to explore possible mechanism for this effect. Thirty-five adult New Zealand white rabbits were used. Skin incisions were made on the back and closed. ATP-vesicles were mixed with a neutral cream for one side of the wounds while the neutral cream alone was used on the other side of the wounds. Laser speckle contrast imaging (LSCI), biomechanical, histological, and immunohistochemical analyses were performed 7 and 14 days after surgery, and macrophage culture was used to test the enhanced collagen production ability. Among them, 10 were used for wound perfusion study and 25 were used for wound biomechanical and histological/immunohistochemical studies. Wound tissue perfusion was reduced after surgery especially in early days. Wound tissue tensile strength, breaking stress, and elasticity were all much higher in the ATP-vesicle treated group than in the cream treated group at days 7 and 14. The healing was complemented by earlier macrophage accumulation, in situ proliferation, followed by direct collagen production. The results were further confirmed by human macrophage culture. It was concluded that intracellular ATP delivery enhanced healing strength of incisional wounds via multiple mechanisms.

Effects of Buprenorphine, Chlorhexidine, and Low-level Laser Therapy on Wound Healing in Mice

Systemic buprenorphine and topical antiseptics such as chlorhexidine are frequently used in research animals to aid in pain control and to reduce infection, respectively. These therapeutics are controversial, especially when used in wound healing studies, due to conflicting data suggesting that they delay wound healing. Low-level laser therapy (LLLT) has been used to aid in wound healing without exerting the systemic effects of therapies such as buprenorphine. We conducted 2 studies to investigate the effects of these common treatment modalities on the rate of wound healing in mice. The first study used models of punch biopsy and dermal abrasion to assess whether buprenorphine HCl or 0.12% chlorhexidine delayed wound healing. The second study investigated the effects of sustained-released buprenorphine, 0.05% chlorhexidine, and LLLT on excisional wound healing. The rate of wound healing was assessed by obtaining photographs on days 0, 2, 4, 7, and 9 for the punch biopsy model in study 1, days 0, 1, 2, 4, 6, 8, 11, and 13 for the dermal abrasion model in study 1, and days 0, 3, 6, and 10 for the mice in study 2. Image J software was used to analyze the photographed wounds to determine the wound area. When comparing the wound area on the above days to the original wound area, no significant differences in healing were observed for any of the treatment groups at any time period for either study. Given the results of these studies, we believe that systemic buprenorphine, topical chlorhexidine, and LLLT can be used without impairing or delaying wound healing in mice.

Effect of the topical Klox fluorescence biomodulation system on the healing of canine surgical wounds

OBJECTIVE

To determine the effect of the Klox fluorescence biomodulation system (Phovia) on the healing of surgical wounds.

STUDY DESIGN

Prospective, blinded, controlled clinical trial.

SAMPLE POPULATION

Healthy dogs undergoing orthopedic surgery (n = 10).

METHODS

Half of the length of each surgical wound was treated with Phovia, and the remaining 50% was treated with saline solution on the first day after surgery and every 3 days until day 13. Wound healing of treated and control areas within each wound was evaluated via macroscopic assessment and histological and immunohistochemical analysis of treated and control wounds.

RESULTS

The areas treated with Phovia achieved lower histology scores (P = .001), consistent with complete re-epithelialization, less inflammation of the dermal layer, and greater and more regular deposition of collagen. According to immunohistochemistry, expression of factor VIII, epidural growth factor, decorin, collagen III, and Ki67 was increased in treated compared with untreated tissues.

CONCLUSION

Phovia therapy improved re-epithelialization, decreased dermal inflammation, and improved matrix formation in uncomplicated cutaneous incisional wounds by regulating the expression of key biological mediators.

CLINICAL SIGNIFICANCE

Phovia may be a beneficial adjunct to promote the healing of incisional wounds.

The Effects of Chronic Preoperative Steroid Therapy on Perioperative Complications Following Elective Posterior Lumbar Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Chronic steroid therapy is used in the treatment of various inflammatory and autoimmune conditions, but it is known to be associated with adverse effects. There remains a gap in the literature regarding the role of chronic steroid therapy in predisposing patients to perioperative complications following elective posterior lumbar fusion (PLF). We aimed to identify the effects of chronic preoperative steroid therapy on 30-day perioperative complications in patients undergoing PLF.

METHODS

A retrospective analysis was performed using the 2011-2014 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. We identified 22 903 patients who underwent elective PLF. There were 849 patients (3.7%) who received chronic preoperative steroid therapy. Univariate and multivariate analyses were performed to examine steroid therapy as an independent risk factor for 30-day perioperative complications. A subgroup analysis of patients on chronic steroid therapy was then performed to identify additional patient characteristics that further increased the risk for perioperative complications.

RESULTS

Chronic preoperative steroid therapy was an independent risk factor for 7 perioperative complications, including superficial surgical site infection (SSI), deep SSI, wound dehiscence, urinary tract infection, pulmonary embolism, nonhome discharge, and readmission. Subgroup analysis demonstrated that morbid obesity further predisposed patients on chronic steroid therapy to an increased risk of superficial SSI and wound dehiscence.

CONCLUSIONS

Patients on chronic preoperative steroid therapy are at increased risk of multiple perioperative complications following elective PLF, particularly surgical site complications and venous thromboembolic events. This risk is further elevated in patients who are morbidly obese.

The Roles of Opioid Receptors in Cutaneous Wound Healing

The process of recovery from skin wounding can be protracted and painful, and scarring may lead to weakness of the tissue, unpleasant sensations such as pain or itch, and unfavorable cosmetic outcomes. Moreover, some wounds simply fail to heal and become a chronic burden for the sufferer. Understanding the mechanisms underlying wound healing and the concomitant sensory disorders and how they might be manipulated for therapeutic benefit has attracted much interest in recent years, and here we discuss the latest developments in the field, focusing on the emergent roles of the peripheral opioid receptor (OPr) system.

Morphine Induces Fibroblast Activation through Up-regulation of Connexin 43 Expression: Implication of Fibrosis in Wound Healing

Morphine is the most effective drugs for attenuating various types of severe pain, but morphine abuse carries a high risk of systemic fibrosis. Our previous have indicated that systemic administration of morphine hinders angiogenesis and delays wound healing. Here we have explained the pathological mechanism underlying the effect of morphine on wound healing. To determine how morphine affects wound healing, we first created a wound in mice treated them with a combination of a low doses (5 mg/kg/day) and high doses (20 or 30 mg/kg/day) of morphine. An In vivo study revealed that high-dose morphine-induced abnormal myofibroblasts persist after the end of wound healing because of connexin 43 (Cx43) upregulation. High-dose morphine-induced Cx43 increased the expression levels of focal adhesion molecules, namely fibronectin and alpha-smooth muscle actin (α-SMA) through the activation of transforming growth factor (TGF)-β1 signaling. In addition, we found that Cx43 contributed to TGF-βRII/ Smad2/3 signaling for regulating the differentiation of fibroblasts into myofibroblasts during high-dose morphine exposure. In conclusion, the abnormal regulation of Cx43 by morphine may induce systemic fibrosis because of abnormal myofibroblast function.

Relationship between opioid treatment and rate of healing in chronic wounds

Opioids are routinely used analgesics in patients with chronic wounds; however the impact of opioid exposure on wound healing is poorly understood. The purpose of this study was to investigate the association between opioid exposure and wound outcome in the Wound Etiology and Healing study. This longitudinal observational study was conducted on 450 subjects enrolled in the Wound Etiology and Healing biorepository. Data were collected prospectively including baseline characteristics, pain score, longitudinal opioid exposure, and total wound surface area (tWSA). Data were analyzed using static multivariate models, fixed-effects mixed models, and time to event analysis. Using fixed-effects models, opioid dose was significantly associated with tWSA after accounting for the effects of pain score and baseline co-variates (p < 0.0001). For each 1-unit increase in ln(opioid dose + 1) the ln(tWSA + 1) increased by 0.16 units (95% confidence interval 0.13-0.19, p < 0.0001). Visits where opioids were present had ln(tWSA + 1) 0.48 units larger (95% confidence interval 0.38-0.58, p < 0.0001) than visits with no opioid exposure. Using time-to-event analysis, patients who never received opioids healed faster than those who received opioids (log-rank chi-square 11.00, p  = 0.0009). Using Cox regression analysis, patients with mean opioid dose ≥10 mg were significantly less likely to heal than those with no opioid (HR 0.67 [0.49-0.91], p = 0.011) after adjusting for wound size. Patients with opioid dose >0 to <10 mg had a similar hazard of not healing as those with no opioid exposure (HR 0.88 [0.65-1.19], p = 0.40). In conclusion, opioid analgesics are commonly prescribed to patients with chronic wounds; however, the data presented suggest that opioid exposure is associated with reduced likelihood of healing in patients with chronic wounds. Whether this is a causal relationship will require further study.

Biologic versus Synthetic Mesh Reinforcement: What are the Pros and Cons?

Preserving patients' native tissues has posed many challenges for surgeons. Increased life expectancy is leading to a proportionately older surgical population with weaker tissues. The growing population of morbidly obese patients in addition to those with multiple comorbidities which influence the native strength and perfusion of tissues compounds the surgeon's challenge. Certainly, there is a rising demand for materials to replace or augment a patient's native tissue when it has been compromised. Over time, the number of products available has increased substantially. The ideal substitute, however, is debatable. The manufacturing and processing of these materials has become more complex and this has resulted in a significant increase in cost. The composition of the mesh, clinical scenario, and operative technique all interact to impact the long-term results. Surgeons require a thorough understanding of these products to guide proper selection and use, to ensure optimal outcomes for patients, and to properly steward financial resources. This review will outline the properties of commonly used materials, highlighting the strength and weakness of each. It will then discuss recommendations regarding mesh selection, coding, and reimbursement. While general principles and trends can be highlighted, further studies of biologic versus synthetic meshes are clearly necessary.

Smoking and its effects on the healing process of chronic wounds

Smoking has a negative impact on skin health. Numerous studies have effectively linked smoking with delayed wound healing and healing complications. Research has identified cigarette smoking affects wound healing at a cellular level. Reducing fibroblast activity and keratinocyte migration. Such is the concern around the affects that smoking has on wound healing that some question whether smoking abstinence should be a pre requisite before some surgical procedures. This article will discuss current research and clinical studies that have investigated impaired wound healing as a result of cigarette smoking.

The role of wound healing and its everyday application in plastic surgery: a practical perspective and systematic review

BACKGROUND

After surgery it is often recommended that patients should refrain from strenuous physical activity for 4-6 weeks. This recommendation is based on the time course of wound healing. Here, we present an overview of incisional wound healing with a focus on 2 principles that guide our postoperative recommendations: the gain of tensile strength of a wound over time and the effect of mechanical stress on wound healing.

METHODS

A systematic search of the English literature was conducted using OVID, Cochrane databases, and PubMed. Inclusion criteria consisted of articles discussing the dynamics of incisional wound healing, and exclusion criteria consisted of articles discussing nonincisional wounds.

RESULTS

Experiments as early as 1929 laid the groundwork for our postoperative activity recommendations. Research using animal models has shown that the gain in tensile strength of a surgical wound is sigmoidal in trajectory, reaching maximal strength approximately 6 weeks postoperatively. Although human and clinical data are limited, the principles gained from laboratory investigation have provided important insights into the relationship among mechanical stress, collagen dynamics, and the time course of wound healing.

CONCLUSION

Our postoperative activity recommendations are based on a series of animal studies. Clinical research supporting these recommendations is minimal, with the most relevant clinical data stemming from early motion protocols in the orthopedic literature. We must seek to establish clinical data to support our postoperative activity recommendations so that we can maximize the physiologic relationships between wound healing and mechanical stress.

Alterations in serum MMP and TIMP concentrations following chronic heroin abuse

Abstract Context: Although opiate abuse is known to affect matrix metalloproteinases (MMPs), data on these enzymes and their tissue inhibitors in heroin addicts are scarce.

OBJECTIVE

In the present study, we determined serum concentrations of MMP-2, MMP-9, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in heroin users, and compared them with healthy individuals. We evaluated whether 21 d of abstinence are adequate to reverse the effect of opiates and we compared seropositive with seronegative, for anti-HCV antibodies, heroin users.

MATERIALS AND METHODS

Twenty-six heroin-dependent male volunteers and an equal number of healthy individuals participated in this study. ELISA was used to assess the serum levels of MMP-2, MMP-9, TIMP-1 and TIMP-2. Heroin users were assessed both upon admission and upon completion of a 21-d detoxification program.

RESULTS

Serum TIMP-1 concentrations were significantly lower and the ratios MMP-2/TIMP-1, MMP-9/TIMP-1 and MMP-2/TIMP-2 were significantly higher in heroin users compared to healthy individuals. Heroin users who were seropositive had lower MMP concentrations, as well as lower MMP/TIMP ratios, compared to those who were seronegative.

DISCUSSION

Our results showed that in heroin-addicted individuals, and especially those who are positive for anti-HCV antibodies, the balance between MMPs and TIMPs in serum is disrupted and this disruption cannot be restored within 21 d of abstinence.

CONCLUSION

Chronic heroin abuse disrupts the balance between MMPs and TIMPs in serum and this effect is not reversible within 21 d of abstinence.

Endogenous opiates and behavior: 2011

This paper is the thirty-fourth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2011 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration (Section 16); and immunological responses (Section 17).

Effect of local anaesthetic infiltration with bupivacaine and ropivacaine on wound healing: a placebo-controlled study

Infiltration of surgical wounds with long-acting local anaesthetics (LA) is used to reduce postoperative incisional pain. We hypothesised that infiltration with LA interferes with wound healing in rats. Seventy-two rats were allocated into nine groups. After intraperitoneal anaesthesia, the interscapular dorsal region was infiltrated with equivolumes of saline, 0·5% bupivacaine or ropivacaine, in a randomised double-blind fashion. A standardised incision was performed in the infiltrated area and sutured closed. The rats were euthanised on the 3rd or 14th day after the operation and tissue from the incision site was subjected to histochemical analyses and mechanical testing (MT). Compared with the control group, bupivacaine displayed a significant increase in the macrophage number on day 3 (+63% versus +27% for ropivacaine). The transforming growth factor β-1 expression had a significant increase in the LA (versus saline) groups, +63% in ropivacaine group and +115% in bupivacaine group on day 3 (P < 0·05). The collagen fibres as measured by dyed area were significantly higher in the bupivacaine group on day 3 (+56%, P < 0·01 versus +15% for ropivacaine). CD34 was reduced in bupivacaine group (-51%, P < 0·05 versus +3% for ropivacaine). On day 14, no statistical differences were observed in either LA group (versus saline) with respect to histopathologic or inflammatory mediators. MT on day 14 showed no differences between the LA and saline groups. The LA-induced increases in histological markers did not extend beyond the third day, suggesting that wound infiltration with long-acting LA does not impair the wound healing process in rats.

Effect of opium dependency on secondary intention wound healing in a rat model: an experimental study

Opium dependency is a social and health problem in some middle eastern countries like Iran. Many of these people may require surgery. This study investigates the effects of opium dependency on histological parameters of secondary intention wound healing in rat. A full-thickness wound (2 × 2 cm in diameters) was created on the dorsum of two groups of rats, a normal control group and a second group of rat depended to opium (Badawy's method). Several times during 14 days postwounding, the wound was excised with peripheral margins of normal skin and was evaluated for cellular population, reepithelialisation and revascularisation. Results are presented as the mean ± standard error. Data were compared by an unpaired t-test or analysis of variance. Histological examination of the wound tissue showed evidence of increased population of fibroblasts, decreased recruitment of neutrophile and plateau of macrophage cells in opium depended animals comparing with control group. In the depended animals, reepithelialisation was seen to be enhanced significantly, while prohibiting progression of revascularisation. This study shows that opium dependency enhances reepitheliazation as well as tissue recruitment of fibroblasts; thereby probable enhancement of secondary intention wound healing.

Extracorporeal shock wave treatment improves incisional wound healing in diabetic rats

Impaired wound healing in surgical patients with diabetes increases the incidence of infection, prolongs hospitalization, and even increases the rate of mortality. Low-energy extracorporeal shock wave treatment (ESWT) was reported to accelerate chronic wound healing by promoting revascularization and tissue regeneration; however, it is not known if ESWT could also improve healing of acute surgical incisional wounds in diabetes. In this study, using a rat model of diabetes, we investigated the effect of low-energy ESWT on collagen content in wound tissues and its efficacy in incisional wound healing. A single dorsal incisional wound was inflicted in streptozotocin-induced diabetic rats, and they received ESWT at different time post-wounding. Rats were sacrificed on days 7 and 14 post-wounding. Wound breaking strength, hydroxyproline content, histological characteristics and the expression of transforming growth factor beta 1 (TGF-β1) were analyzed. As a result, the wound breaking strength was significantly enhanced and the hydroxyproline content in wound tissues was increased at each time point examined. The number of fibroblasts was signicantly increased, and the new collagen fibers were more abundant at the wound site after ESWT. Furthermore, the expression of TGF-β1 was up-regulated after ESWT on day 7 post-wounding. These results suggest that low-energy ESWT can increase collagen content, enhance wound breaking strength and improve the healing of incisional wound in diabetic rats. The increased collagen content may be attributed, at least in part, to the up-regulation of TGF-β1 expression in wound tissues.