Antifungal activity of designed α-helical antimicrobial peptides.

Antimicrobial resistance (AMR) has become a major global health concern prompting the quest for new antibiotics with higher efficiency and less proneness to drug resistance. Antimicrobial peptides (AMPs) offer such properties and have therefore gained increasing attention as a new generation of antibiotics to overcome AMR. In an attempt to develop new highly selective and highly efficient antifungal peptides, a sequence (named At1) originating from the natural AMP Ponericin-W1 was used as a lead sequence for rational design of a series of short cationic antifungal peptides named At2-At12. The charge, hydrophobicity, and terminal amino acids of the peptides were modified in a systematic way to investigate the effect of such structural changes on the biological activity of the peptides. Among all the designed peptides, three peptides (coded as At3, At5 and At10) exhibited high antifungal activity without any significant hemolytic activity in human red blood cells. The higher selectivity of these peptides for fungal cells over human cells was further confirmed in cocultures of Candida albicans and human foreskin fibroblasts. These three peptides lacked any hydrophilic residues in their hydrophobic domain, contained lysine residues in their hydrophilic region and had an overall charge of 7+. They also had a higher helical content in microbial membrane mimicking DPPG SUVs than the rest of the peptides. The fungi did not develop any resistance to the designed antifungal peptides even after 25 generations indicating low AMR. At5 was also used in vivo for the treatment of wounds infected with Candida albicans in mice and showed superiority over fluconazole for treating infection and accelerating wound healing. There was an interplay between the hydrophobicity and positive charge density to determine the antifungal activity of the peptides. The results from this study suggest this class of antifungal peptides as promising candidates for antifungal drugs with high efficiency, high biocompatibility and low propensity for drug resistance.

Surfactant like peptides for targeted gene delivery to cancer cells.

Surfactant like peptides (SLPs) are a class of amphiphilic peptides widely used for drug delivery and tissue engineering. However, there are very few reports on their application for gene delivery. The current study was aimed at development of two new SLPs, named (IA)4K and (IG)4K, for selective delivery of antisense oligodeoxynucleotides (ODNs) and small interfering RNA (siRNA) to cancer cells. The peptides were synthesized by Fmoc solid phase synthesis. Their complexation with nucleic acids was studied by gel electrophoresis and DLS. The transfection efficiency of the peptides was assessed in HCT 116 colorectal cancer cells and human dermal fibroblasts (HDFs) using high content microscopy. The cytotoxicity of the peptides was assessed by standard MTT test. The interaction of the peptides with model membranes was studied using CD spectroscopy. Both SLPs delivered siRNA and ODNs to HCT 116 colorectal cancer cells with high transfection efficiency which was comparable to the commercial lipid-based transfection reagents, but with higher selectivity for HCT 116 compared to HDFs. Moreover, both peptides exhibited very low cytotoxicity even at high concentrations and long exposure time. The current study provides more insights into the structural features of SLPs required for nucleic acid complexation and delivery and can therefore serve as a guide for the rational design of new SLPs for selective gene delivery to cancer cells to minimize the adverse effects in healthy tissues.

Antimicrobial peptide functionalized gold nanorods combining near-infrared photothermal therapy for effective wound healing.

Photothermal therapy using laser activated gold nanorods (AuNRs) is a strategy for treatment of bacterial infections. Nevertheless, it also exerts cytotoxicity against human cells which leads to adverse effects in healthy human tissues and limits the applicable dose. Functionalization of AuNRs with a selective antimicrobial peptide (AMP) with higher selectivity for bacteria over human cells is a promising strategy for increasing the selectivity of the AuNRs for bacteria, hence increasing their cellular uptake by the bacteria in order to achieve stronger antimicrobial effects with lower doses of AuNRs without damaging the human cells. In this study, the surface of AuNRs was functionalized with a short AMP named C-At5 and the efficiency of the peptide functionalized AuNRs in killing gram-positive and gram-negative bacteria was evaluated in vitro as well as their potential for facilitating wound healing in a mouse model of wound infection with and without application of laser. The peptide-conjugated AuNRs exhibited higher antibacterial activity in vitro compared to the plain AuNRs both in the presence and absence of laser irradiation. Furthermore, AuNR@C-At5 had very low toxicity against human skin fibroblasts and human red blood cells indicating their higher biocompatibility compared to the plain AuNRs. Treatment of wounded mice with AuNR@C-At5 accelerated the wound healing process which was further enhanced by applying laser. The system developed in this study has great potential for customization for specific antimicrobial or antifungal therapy via conjugation of different types of AMPs with higher selectivity and can therefore serve as a guide for any future attempts in this regard.

Anticancer effect of rationally designed α-helical amphiphilic peptides.

Anticancer peptides (ACPs) have attracted increasing attention in cancer therapy due to their unique mechanism of action on cancer cells. The main challenge is to establish the correlation between their physicochemical properties and their selectivity and anticancer effect, leading to a clear design strategy. In this study, a series of new α-helical short peptides (coded At1-At12) with different anticancer activities were systematically designed with different amphiphilicity based on a natural α-helical antimicrobial peptide (AMP) derived from ant. Three of the designed peptides, At7, At10 and At11, showed considerable anticancer activity with low toxicity to normal skin fibroblasts. The high selectivity of the peptides is attributed to their balanced amphiphilicity and cationic nature which favours binding to the outer membrane of negatively charged cancer cells over the neutral membrane of normal mammalian cells. In addition to rapid membrane penetration, the designed peptides also damaged the mitochondria and induced mitochondrial membrane depolarization. Moreover, these peptides were found to induce apoptosis in cancer cells by up-regulating the expression of apoptotic proteins Bax and Caspase-3, down-regulating the apoptotic protein Bcl-2, and activating the Caspase enzyme-linked reaction. The results of this study reveal the potential of these peptides for clinical applications, and provide a guidance for further development of highly selective anticancer medications.

Highly selective performance of rationally designed antimicrobial peptides based on ponericin-W1.

Antimicrobial peptides (AMPs) or host-defence peptides act by penetrating and disrupting the bacterial membranes and are therefore less prone to antimicrobial resistance (AMR) compared to conventional antibiotics. However, there are still many challenges in the clinical application of the naturally occurring AMPs which necessitates further studies to establish the relationship between the chemical structure of AMPs and their antimicrobial activity and selectivity. Herein, we report a study on the relationship between the chemical structure and the biological activity of a series of rationally designed AMPs derived from Ponericin-W1, a naturally occurring AMP from ants. The peptides were designed by modification of the hydrophobic and hydrophilic regions of the lead peptide sequence in a systematic way. Their antibacterial and hemolytic activities were determined in vitro. The antibacterial activity of a representative peptide, At5 was also tested in a mouse model of skin wound infection. Furthermore, the relationship between the physicochemical properties of the peptides and their antibacterial activity was investigated. Replacing the cationic amino acids in the hydrophobic region of the peptides with hydrophobic amino acids enhanced their antibacterial activity and increasing the number of cationic amino acids in the hydrophilic region reduced their toxicity to human red blood cells and thus improved their selectivity for bacteria. Four of the designed peptides, coded as At3, At5, At8, and At10, displayed considerable antibacterial activity and high selectivity for bacteria. At5 also accelerated the wound healing in mice indicating high in vivo efficiency of this peptide. The peptides were more effective against Gram-negative bacteria and no AMR was developed against them in the bacteria even after 25 generations. The results from this study can provide a better understanding of the structural features required for strong antibacterial activity and selectivity, and serve as a guide for the future rational design of AMPs.

Peptide-functionalised magnetic silk nanoparticles produced by a swirl mixer for enhanced anticancer activity of ASC-J9.

Silk fibroin is an FDA approved biopolymer for clinical applications with great potential in nanomedicine. However, silk-based nanoformulations are still facing several challenges in processing and drug delivery efficiency (such as reproducibility and targetability), especially in cancer therapy. To address these challenges, robust and controllable production methods are required for generating nanocarriers with desired properties. This study aimed to develop a novel method for the production of peptide-functionalized magnetic silk nanoparticles with higher selectivity for cancer cells for targeted delivery of the hydrophobic anticancer agent ASC-J9. A new microfluidic device with a swirl mixer was designed to fabricate magnetic silk nanoparticles (MSNP) with desired size and narrow size distribution. The surface of MSNPs was functionalized with a cationic amphiphilic anticancer peptide, G(IIKK)3I-NH2 (G3), to enhance their selectivity towards cancer cells. The G3-MSNPs increased the cellular uptake and anticancer activity of G3 in HCT 116 colorectal cancer cells compared to free G3. Moreover, the G3-MSNPs exhibited considerably higher cellular uptake and cytotoxicity in HCT 116 colorectal cancer cells compared to normal cells (HDFs). Encapsulating ASC-J9 in G3-MSNPs resulted in augmented anticancer activity compared to free ASC-J9 and non-functionalized ASC-J9 loaded MSNPs within its biological half-life. Hence, functionalizing MSNPs with G3 enabled targeted delivery of ASC-J9 to cancer cells and enhanced its anticancer effect. Functionalization of nanoparticles with anticancer peptides could be regarded as a new strategy for targeted delivery and enhanced efficiency of anticancer drugs. Furthermore, the microfluidic device introduced in this paper offers a robust and reproducible method for fabrication of small sized homogenous nanoparticles.

Optimization of large-scale manufacturing of biopolymeric and lipid nanoparticles using microfluidic swirl mixers.

Nanoparticles (NPs) have great potential as efficient drug delivery systems (DDSs) that have been widely used in cancer therapy and vaccines especially in the past decade. The rise in demand from the pharmaceutical industry drives the growth of the global NPs market. However, complex production processes have hindered the market growth. Therefore, the development of advanced preparation techniques such as microfluidics is required to improve productivity and controllability. In this study, we present a novel microfluidic design (swirl mixer) that helps accelerating the translation of many DDSs from laboratory to clinical application. The new swirl mixer provides high production rate, reproducibility, and precise control of particle size with low polydispersity index (PDI). To assess the performance of the swirl mixer, two different types of nanoformulations were used: silk nanoparticles (SNPs) and lipid nanoparticles (LNPs). The microfluidic device produced NPs efficiently with high productivity and allowed for tuning the mean size and size distribution by changing multiple processing parameters.

Current state of the art in peptide-based gene delivery.

Gene therapy involves introduction of exogenous genetic materials into the cells in order to correct a specific pathological condition. However, efficient delivery of the genetic materials to the target cells is hampered by a number of extracellular and intracellular barriers which necessitates the use of gene vectors. Despite the high transfection efficiencies of the viral vectors, their immunogenicity and complex manufacturing procedures has led to the quest for development of non-viral vectors with lower toxicity and easier fabrication from a variety of materials such as polymers and lipids. More recently, peptides have been introduced as new promising biomaterials for gene delivery owing to their desirable physicochemical properties and their biocompatibility. Various naturally derived, synthetic or hybrid peptides with varying sizes and structural features have been used for gene delivery. In this review, a summary of recent advances in the development of peptide-based gene delivery systems for delivery of different types of genetic materials to different types of cells/tissues has been provided. The focus of this review is on gene delivery systems consisting merely of peptides without incorporation of polymers or lipids. The transfection efficiencies of different groups of peptides and their abilities for targeted gene delivery have been viewed in the context of their chemical structures in order to provide an insight into the structural features required for efficient gene delivery by different classes of peptides and to serve as a guide for rational design of new types of peptide vectors for highly efficient and tissue-specific gene delivery.

Rationally designed cationic amphiphilic peptides for selective gene delivery to cancer cells.

Gene therapy has gained increasing attention as an alternative to pharmacotherapy for treatment of various diseases. The extracellular and intracellular barriers to gene delivery necessitate the use of gene vectors which has led to the development of myriads of gene delivery systems. However, many of these gene delivery systems have pitfalls such as low biocompatibility, low loading efficiency, low transfection efficiency, lack of tissue selectivity and high production costs. Herein, we report the development of a new series of short cationic amphiphilic peptides with anticancer activity for selective delivery of small interfering RNA (siRNA) and antisense oligodeoxynucleotides (ODNs) to cancer cells. The peptides consist of alternating dyads of hydrophobic (isoleucine (I) or leucine (L)) and hydrophilic (arginine (R) or lysine (L)) amino acids. The peptides exhibited higher preference for transfection of HCT 116 colorectal cancer cells compared to human dermal fibroblasts (HDFs) and induced higher level of gene silencing in the cancer cells. The nucleic acid complexation and transfection efficiency of the peptides was a function of their secondary structure, their hydrophobicity and their C-terminal amino acid. The peptides containing L in their hydrophobic domain formed stronger complexes with siRNA and successfully delivered it to the cancer cells but were unable to release their cargo inside the cells and therefore could not induce any gene silencing. On the contrary, the peptides containing I in their hydrophobic domain were able to release their associated siRNA and induce considerable gene silencing in cancer cells. The peptides exhibited higher selectivity for colorectal cancer cells and induced less gene silencing in fibroblasts compared to the lipid-based commercial transfection reagent DharmaFECT™ 1. The results from this study can serve as a tool for rational design of new peptide-based gene vectors for high selective gene delivery to cancer cells.

Correlation between the secondary structure and surface activity of ß-sheet forming cationic amphiphilic peptides and their anticancer activity.

Cancer is one of the main causes of death worldwide. The current cancer treatment strategies often lack selectivity for cancer cells resulting in dose-limiting adverse effects and reduced quality of life. Recently, anticancer peptides (ACPs) have emerged as an alternative treatment with higher selectivity, less adverse effects, and lower propensity for drug resistance. However, most of the current studies on the ACPs are focused on α-helical ACPs and there is lack of systematic studies on ß-sheet forming ACPs. Herein we report the development of a new series of rationally designed short cationic amphiphilic ß-sheet forming ACPs and their structure activity relationship. The peptides had the general formula (XY1XY2)3, with X representing hydrophobic amino acids (isoleucine (I) or leucine (L)), Y1 and Y2 representing cationic amino acids (arginine (R) or lysine (K)). The cytotoxicity of the designed ACPs in HCT 116 colorectal cancer, HeLa cervical cancer and human dermal fibroblast (HDF) cells was assessed by MTT test. The physicochemical properties of the peptides were characterized by various techniques including RP-HPLC, LC-MS, and Circular Dichroism (CD) spectroscopy. The surface activity of the peptides at the air-water interface and their interaction with the lipid monolayers as models for cell membranes were studied by Langmuir trough. The peptides consisting of I with R and K had selective anticancer activity while the combination of L and R diminished the anticancer activity of the peptides but rendered them more toxic to HDFs. The anticancer activity of the peptides was directed by their surface activity (amphiphilicity) and their secondary structure in hydrophobic surfaces including cancer cell membranes. The selectivity of the peptides for cancer cells was a result of their higher penetration into cancer cell membranes compared to normal cell membranes. The peptides exerted their anticancer activity by disrupting the mitochondrial membranes and eventually apoptosis. The results presented in this study provide an insight into the structure-activity relationship of this class of ACPs which can be employed as guidance to design new ACPs with improved anticancer activity and lower toxicity against normal cells.

Rationally designed short cationic α-helical peptides with selective anticancer activity.

HYPOTHESIS: Naturally derived or synthetic anticancer peptides (ACPs) have emerged as a new generation of anticancer agents with higher selectivity for cancer cells and less propensity for drug resistance. Despite the structural diversity of ACPs, α-helix is the most common secondary structure among them. Herein we report the development of a new library of short cationic amphiphilic α-helical ACPs with selective cytotoxicity against colorectal and cervical cancer. EXPERIMENTS: The peptides had a general formula C(XXYY)3 with C representing amino acid cysteine (providing a -SH group for molecular conjugation), X representing hydrophobic amino acids (isoleucine (I) or leucine (L)), and Y representing cationic amino acids (arginine (R) or lysine (K)). Two variants of the peptides were synthesized by adding additional Isoleucine residues to the C-terminal and replacing the N-terminal cysteine with LC-propargylglycine (LC-G) to investigate the effect of N-terminal and C-terminal variation on the anticancer activity. The structure and physicochemical properties of the peptides were determined by RP-HPLC, LC-MS and CD spectroscopy. The cytotoxicity of the peptides in different cell lines was assessed by MTT test, cell proliferation assay and mitochondrial damage assay. The mechanism of cell selectivity of the peptides was investigated by studying their interfacial behaviour at the air/water and lipid/water interface using Langmuir trough. FINDINGS: The peptides consisting of K residues in their hydrophilic domains exhibited more selective anticancer activity whereas the peptides containing R exhibited strong toxicity in normal cells. The anticancer activity of the peptides was a function of their helical content and their hydrophobicity. Therefore, the addition of two I residues at C-terminal enhanced the anticancer activity of the peptides by increasing their hydrophobicity and their helical content. These two variants also exhibited strong anticancer activity against colorectal cancer multicellular tumour spheroids (MCTS). The higher toxicity of the peptides in cancer cells compared to normal cells was the result of higher penetration into the negatively charged cancer cell membranes, leading to higher cellular uptake, and their cytotoxic effect was mainly exerted by damaging the mitochondrial membranes leading to apoptosis. The results from this study provide a basis for rational design of new α-helical ACPs with enhanced anticancer activity and selectivity.

Stiffness-tuneable nanocarriers for controlled delivery of ASC-J9 into colorectal cancer cells.

HYPOTHESIS: One of the main challenges in cancer therapy is the poor water solubility of many anticancer drugs which results in low bioavailability at the tumour sites and reduced efficacy. The currently available polymer-based anticancer drug delivery systems often suffer from low encapsulation efficiency, uncontrolled release, and lack of long-term stability. Herein, we report the development of novel stiffness-tuneable core-shell nanocarriers composed of naturally derived polymers silk fibroin (SF) and sodium alginate (SA) inside a liposomal shell for enhanced cellular uptake and controlled release of hydrophobic anticancer agent ASC-J9 (Dimethylcurcumin). It is anticipated that the stiffness of the nanocarriers has a significant effect on their cellular uptake and anticancer efficacy. EXPERIMENTS: The nanocarriers were prepared by thin film hydration method followed by extrusion and cross-linking of SA to obtain a uniform size and shape, avoiding harsh processing conditions. The structural transformation of SF in the nanocarriers induced by SA crosslinking was determined using Fourier transform infrared (FTIR) spectroscopy. The size, zeta potential, morphology and stiffness of the nanocarriers were measured using dynamic light scattering (DLS), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Drug loading and release were measured using UV-Vis spectrophotometry. The cellular uptake and anticancer efficacy of the nanocarriers were studied in HCT 116 human colorectal adenocarcinoma cells and 3D tumour spheroids using high content microscopy. FINDINGS: The synthesized nanocarriers had high encapsulation efficiency (62-78%) and were physically stable for up to 5 months at 4 ˚C. The release profile of the drug from the nanocarriers was directed by their stiffness and was easily tuneable by changing the ratio of SF to SA in the core. Furthermore, the designed nanocarriers improved the cellular uptake and anticancer activity of ASC-J9, and enhanced its tumour penetration in HCT 116 3D colorectal cancer spheroids. These findings suggest that the designed core-shell nanocarriers can be used as a highly efficient drug delivery system for cancer therapy.

Silk Fibroin as a Functional Biomaterial for Drug and Gene Delivery.

Silk is a natural polymer with unique physicochemical and mechanical properties which makes it a desirable biomaterial for biomedical and pharmaceutical applications. Silk fibroin (SF) has been widely used for preparation of drug delivery systems due to its biocompatibility, controllable degradability and tunable drug release properties. SF-based drug delivery systems can encapsulate and stabilize various small molecule drugs as well as large biological drugs such as proteins and DNA to enhance their shelf lives and control the release to enhance their circulation time in the blood and thus the duration of action. Understanding the properties of SF and the potential ways of manipulating its structure to modify its physicochemical and mechanical properties allows for preparation of modulated drug delivery systems with desirable efficacies. This review will discuss the properties of SF material and summarize the recent advances of SF-based drug and gene delivery systems. Furthermore, conjugation of the SF to other biomolecules or polymers for tissue-specific drug delivery will also be discussed.

A Review of Curcumin and Its Derivatives as Anticancer Agents.

Cancer is the second leading cause of death in the world and one of the major public health problems. Despite the great advances in cancer therapy, the incidence and mortality rates of cancer remain high. Therefore, the quest for more efficient and less toxic cancer treatment strategies is still at the forefront of current research. Curcumin, the active ingredient of the Curcuma longa plant, has received great attention over the past two decades as an antioxidant, anti-inflammatory, and anticancer agent. In this review, a summary of the medicinal chemistry and pharmacology of curcumin and its derivatives in regard to anticancer activity, their main mechanisms of action, and cellular targets has been provided based on the literature data from the experimental and clinical evaluation of curcumin in cancer cell lines, animal models, and human subjects. In addition, the recent advances in the drug delivery systems for curcumin delivery to cancer cells have been highlighted.

Optimization of particle size and encapsulation efficiency of vancomycin nanoparticles by response surface methodology.

CONTEXT: Treating vancomycin-resistant Staphylococcus aureus strains requires high doses of vancomycin, which might lead to adverse reactions such as nephrotoxicity and "red neck syndrome". Use of nanotechnology for antibiotic delivery is a promising approach to overcome antibiotic-resistance. OBJECTIVE: The objective of this study was optimizing the particle size and encapsulation efficiency (EE) of vancomycin nanoparticles prepared from chitosan. MATERIALS AND METHODS: The nanoparticles were prepared by ionotropic gelation method, at different combinations of chitosan concentration, chitosan/tripolyphosphate mass and vancomycin/chitosan mass, using Box-Behnken experimental design. Dynamic light scattering and ultracentrifugation were used to measure the nanoparticle size and EE, respectively. Vancomycin was quantified in samples by spectrophotometery. The optimum conditions were determined by subsequent regression analysis and multicriteria decision analysis of the output data. RESULTS: The nanoparticle size and EE were greatly influenced by the independent variables, which had interactive effects on both responses. The optimum conditions for production of nanoparticles were chitosan concentration of 0.5-1.2 mg/ml, chitosan/tripolyphosphate mass ratio of 3-3.5 and vancomycin/chitosan mass ratio of 1, which yielded nanoparticles between 130 and 150 nm with encapsulation efficiencies of 60-69%. CONCLUSIONS: The size and EE of vancomycin nanoparticles were optimized by the proposed procedure.

Optimization of size and encapsulation efficiency of 5-FU loaded chitosan nanoparticles by response surface methodology.

The objective of this study was to optimize the particle size and encapsulation efficiency of chitosan nanoparticles loaded with 5-Fluorouracil (5-FU) by response surface methodology. Nanoparticles were prepared by ionic gelation method from chitosan and penta sodium triphosphate (TPP) at different combinations of chitosan viscosity, chitosan concentration and chitosan/TPP mass ratio according to the Box-Behnken experimental design. The particle size and encapsulation efficiency of prepared particles were measured by dynamic light scattering and UV spectroscopy, respectively, and the obtained data were subjected to multiple linear regression analysis followed by multi-attribute utility analysis to obtain a model for prediction of the optimum response. The optimum conditions for the production of 5-FU loaded chitosan nanoparticles were found to be low viscosity chitosan 0.5-1 mg/mL, middle viscosity chitosan 0.5-0.8 mg/mL and high viscosity chitosan 0.5-0.75 mg/mL and chitosan/TPP mass ratio of 4 or 6, yielding nanoparticles at the average diameter range of 114-188 nm and encapsulation efficiencies between 42-55%.

Efficacy of 10% sucralfate ointment in the reduction of acute postoperative pain after open hemorrhoidectomy: a prospective, double-blind, randomized, placebo-controlled trial.

BACKGROUND: The aim of the present study was to evaluate the efficacy of 10 % sucralfate ointment in the reduction of acute postoperative pain after open hemorrhoidectomy. METHODS: A total of 48 patients (24 men and 24 women) between 20 and 70 years of age who underwent open hemorrhoidectomy were included in this prospective, double-blind, randomized, controlled trial and were randomly divided into two groups (24 in each group), receiving either sucralfate ointment or placebo immediately after surgery and then every 12 h for 14 days. The primary outcome measure was pain intensity measured by a visual analogue scale at different time points after hemorrhoidectomy. RESULTS: The sucralfate group had significantly less pain than the placebo group at 24th h and the 48th h after hemorrhoidectomy (4 ± 1.14 vs 5.08 ± 0.97; P = 0.001 and 3 ± 0.72 vs 4.41 ± 0.8; P < 0.001, respectively), and they consumed lower amounts of analgesics at the same time intervals (12.50 ± 16.48 vs 21.87 ± 15.30 mg of pethidine; P = 0.047 and 152 ± 23 vs 172 ± 29 mg of diclofenac; P = 0.009, respectively). The same trend continued until the end of the trial. CONCLUSIONS: Sucralfate ointment reduced the acute postoperative pain after hemorrhoidectomy.

Efficacy of cholestyramine ointment in reduction of postoperative pain and pain during defecation after open hemorrhoidectomy: results of a prospective, single-center, randomized, double-blind, placebo-controlled trial.

BACKGROUND: The aim of the present study was to evaluate the efficacy of cholestyramine ointment (15 %) in reducing postoperative pain at rest and during defecation after open hemorrhoidectomy. METHODS: A total of 91 patients with third and fourth degree hemorrhoids undergoing open hemorrhoidectomy were included in this prospective, double-blind, randomized controlled trial. The patients were randomly assigned to either cholestyramine ointment or placebo immediately after surgery, 12 h after surgery, and then every 8 h for 14 days. The primary outcomes were intensity of pain at rest and during defecation, measured with a visual analog scale, and the analgesic requirement, measured by amount of tramadol consumption. RESULTS: The cholestyramine group had less postoperative pain than the placebo group at the 24th hour (1.84 ± 2.54 vs. 4.07 ± 3.35; P = 0.001) and 48th hour (0.18 ± 0.88 vs. 3.57 ± 3.45; P < 0.001) and less pain during defecation starting at the 48th hour (2.28 ± 2.96 vs. 4.77 ± 4.09; P = 0.001). Similarly, the average tramadol consumption at hours 24 and 48 was significantly lower for the cholestyramine group (5.32 ± 21.45 vs. 43.18 ± 61.56 mg at 24 h, and 4.48 ± 16.65 vs. 57.63 ± 65.47 mg at 48 h; P < 0.001). The only adverse event was pruritus, which had a lower frequency in the cholestyramine group but the difference was not significant until postoperative week 4 (P < 0.001). CONCLUSIONS: Compared with placebo, cholestyramine ointment (15%) reduced postoperative pain at rest and on defecation, and consequently lowered the analgesic requirement after open hemorrhoidectomy.

Topical diltiazem vs. topical glyceril trinitrate in the treatment of chronic anal fissure: a prospective, randomized, double-blind trial.

BACKGROUND AND STUDY AIMS: Chemical sphincterotomy is a new way for the treatment of chronic anal fissure which avoids the risk of faecal incontinence associated with traditional surgical methods. The aim of this study was to compare topical Diltiazem with topical Glyceril trinitrate in the treatment of chronic anal fissure. PATIENTS AND METHODS: 61 patients (10 Male, 51 Female) between 16-81 years of age with chronic anal fissure were included in this prospective, randomized, double-blind trial. The patients were randomly allocated to either Diltiazem gel (2%) or Glyceril trinitrate ointment (0.2%) and were asked to use the treatment twice daily for 8 weeks. Each patient was reviewed every two weeks; pain scores, healing and side effects were assessed. RESULTS: Healing occurred in 33 of 36 (91.66%) patients treated with Diltiazem after 6 weeks and 15 of 25 (60%) patients treated with Glyceril trinitrate after 8 weeks which shows a significant difference in favour of Diltiazem (P < 0.001). The rest of the patients were either non-compliant or did not heal and underwent surgery. Headache occurred in all of the patients treated with Glyceril trinitrate but none of the patients treated with Diltiazem developed headache. The frequency of other side-effects was also less in patients treated with Diltiazem (P < 0.001). CONCLUSIONS: Diltiazem gel was found to be superior to Glyceril trinitrate ointment due to significantly higher healing rate and fewer side-effects.