Self-assembling Peptide Matrix Research Articles

Fabrication and Characterization of Colorectal Cancer Organoids from SW1222 Cell Line in Ultrashort Self-Assembling Peptide Matrix.

Ultrashort self-assembling peptides (SAPs) can spontaneously form nanofibers that resemble the extracellular matrix. These fibers allow the formation of hydrogels that are biocompatible, biodegradable, and non-immunogenic. We have previously proven that SAPs, when biofunctionalized with protein-derived motifs, can mimic the extracellular matrix characteristics that support colorectal organoid formation. These biofunctional peptide hydrogels retain the original parent peptide's mechanical properties, tunability, and printability while incorporating cues that allow cell-matrix interactions to increase cell adhesion. This paper presents the protocols needed to evaluate and characterize the effects of various biofunctional peptide hydrogels on cell adhesion and lumen formation using an adenocarcinoma cancer cell line able to form colorectal cancer organoids cost-effectively. These protocols will help evaluate biofunctional peptide hydrogel effects on cell adhesion and luminal formation using immunostaining and fluorescence image analysis. The cell line used in this study has been previously utilized for generating organoids in animal-derived matrices.

Successful small-diameter endoscopic hemostasis using a self-assembling peptide matrix for Mallory-Weiss syndrome in a patient with a severe esophageal stricture

Successful small-diameter endoscopic hemostasis using a self-assembling peptide matrix for Mallory-Weiss syndrome in a patient with a severe esophageal stricture

Rapid hemostasis using a self-assembling peptide matrix for midprocedural bleeding in endoscopic sphincterotomy.

Rapid hemostasis using a self-assembling peptide matrix for midprocedural bleeding in endoscopic sphincterotomy.

Effective application of self-assembling peptide matrix with the gel immersion technique and red dichromatic imaging for hemostasis of postendoscopic sphincterotomy bleeding.

Endoscopic sphincterotomy is an essential procedure during endoscopic retrograde cholangiopancreatography (ERCP) for the diagnosis or treatment of pancreaticobiliary disease; however, postendoscopic sphincterotomy bleeding occasionally occurs and is a potentially life-threatening adverse event [1]. Recently, a novel self-assembling peptide matrix (PuraStat; 3-D Matrix Europe SAS, France), which is approved for hemostasis in gastrointestinal endoscopic procedures, was launched [2]. Because of its characteristics, this product is not effective in achieving hemostasis of pooled blood, as the peptide matrix assembles when the solution comes into contact with body fluids. For effective hemostasis, the peptide matrix gel should be applied as close as possible to the bleeding point of the injured vessel wall. Herein, we report the effective application of PuraStat for hemostasis of postendoscopic sphincterotomy bleeding while securing an endoscopic field of view with the gel immersion technique [3] and red dichromatic imaging (RDI; Olympus, Japan) [4] [5] ([Video 1]).

Efficacy and safety of P11-4 for the treatment of periodontal defects in dogs

ObjectivesThis study’s aim was to investigate the safety and performance of a self-assembling peptide matrix (SAPM) P11-4 for the treatment of periodontal disease in a controlled pre-clinical study.Materials and methodsAcute buccal bony dehiscence defects (LxW: 5 × 3 mm) were surgically created on the distal root of four teeth on one mandible side of 7 beagle dogs followed by another identical surgery 8 weeks later on the contralateral side. SAPM P11-4 (with and without root conditioning with 24% EDTA (T1, T2)), Emdogain® (C) and a sham intervention (S) were randomly applied on the four defects at each time point. Four weeks after the second surgery and treatment, the animals were sacrificed, the mandibles measured by micro-computed tomography (µ-CT) and sections of the tissue were stained and evaluated histologically.ResultsClinically and histologically, no safety concerns or pathological issues due to the treatments were observed in any of the study groups at any time point. All groups showed overall similar results after 4 and 12 weeks of healing regarding new cementum, functionality of newly formed periodontal ligament and recovery of height and volume of the new alveolar bone and mineral density.ConclusionA controlled clinical study in humans should be performed in a next step as no adverse effects or safety issues, which might affect clinical usage of the product, were observed.Clinical relevanceThe synthetic SAPM P11-4 may offer an alternative to the animal-derived product Emdogain® in the future.

Prevention of esophageal stricture after circumferential endoscopic submucosal dissection using a modified self-assembling peptide.

Circumferential endoscopic resection (ER) of the esophageal mucosa could find its place in the treatment of dysplastic Barrett's esophagus or extensive squamous cell neoplasia. However, the occurrence of esophageal strictures remains a major complication after ER exceeding 75% of the circumference. The aim of this study was to assess the effect of a modified, pH = 2, self-assembling peptide matrix (4[Arg-Ala-Asp-Ala]) (SAP) on the development of esophageal stricture after circumferential ER in a swine model. We performed a circumferential ER in 35 swine under general anesthesia. Five animals were included in the control group, 11 animals received the SAP matrix immediately after the resection, and 11 received the SAP matrix associated to a local steroid immediately after the resection. Follow-up endoscopy and esophagogram were performed before slaughter and necropsy at day 14. Eight treated animals were kept alive until day 28. At day 14, 27% of the animals in the SAP group developed a symptomatic stricture versus 100% in the control group (P = 0.008) and 50% in the SAP-triamcinolone group (P = 0.11). Application of an SAP matrix after circumferential ER in the swine allowed a significant reduction of the incidence of symptomatic stricture at day 14. Adding triamcinolone brought no significant improvement.

Randomized Clinical Trial investigating Self-Assembling Peptide P11-4 for Treatment of Early Occlusal Caries

Non-invasive caries treatment is a major focus in modern dentistry. The present study was designed to evaluate the effectiveness of monomeric self-assembling peptide P11-4 (SAP P11-4) in combination with fluoride varnish or polymeric self-assembling peptide matrix (SAPM) in treatment of non-cavitated occlusal caries. Ninety children and adolescents were included in this randomized, gold-standard-controlled clinical trial. Test Group 1 received SAP P11-4 and twice fluoride varnish at baseline and Day 180, Test Group 2 received SAP P11-4 on baseline and twice weekly SAPM (home-application), and Control Group received fluoride varnish on baseline and Day 180. Caries progression was measured by laser fluorescence, Nyvad Caries Activity, ICDAS-II-codes, and investigator assessments. Laser fluorescence changes demonstrated superior results for Test Group 1 and 2, as values decreased compared to an increase for the Control Group (p < 0.0005). ICDAS-II codes at Day 360 showed partial regression for Test Group 1 (6.7%) and Test Group 2 (20.0%) and partial progression for Control Group (23.3%) (p < 0.01). Nyvad Caries Activity yielded superior caries inactivation for Test Groups, compared to Control Group (p = 0.002). This trial showed that SAP P11-4, applied either in combination with fluoride varnish or twice weekly SAPM, was a superior treatment for early caries compared to fluoride varnish alone.

An In Vitro Comparison of A Novel Self-Assembling Peptide Matrix Gel and Selected Desensitizing Toothpastes in Reducing Fluid Flow by Dentine Tubular Occlusion

An In Vitro Comparison of A Novel Self-Assembling Peptide Matrix Gel and Selected Desensitizing Toothpastes in Reducing Fluid Flow by Dentine Tubular Occlusion

Application of a self-assembling peptide matrix prevents esophageal stricture after circumferential endoscopic submucosal dissection in a pig model.

IntroductionCircumferential endoscopic submucosal dissection (ESD) allows to treat large esophageal superficial neoplasms, however with a high occurrence of severe esophageal strictures. In a previous work, we demonstrated that the application of a prototype of self-assembling peptide (SAP) matrix on esophageal wounds after a circumferential-ESD delayed the onset of esophageal stricture in a porcine model. The aim of this work was to consolidate these results using the commercialized version of this SAP matrix currently used as a hemostatic agent.Animals and methodsEleven pigs underwent a 5 cm-long circumferential esophageal ESD under general anesthesia. Five pigs were used as a control group and six were treated with the SAP. In the experimental group, 3.5 mL of the SAP matrix were immediately applied on the ESD wound. Stricture rates and esophageal diameter were assessed at day 14 by endoscopy and esophagram, followed by necropsy and histological measurements of inflammation and fibrosis in the esophageal wall.ResultsAt day 14, two animals in the treated group had an esophageal stricture without any symptom, while all animals in the control group had regurgitations and an esophageal stricture (33 vs. 100%, p = 0.045). In the treated group, the mean esophageal diameter at day 14 was 9.5 ± 1 mm vs. 4 ± 0.6 mm in the control group (p = 0.004). Histologically, the neoepithelium was longer in the SAP treated group vs. the control (3075 μm vs. 1155μm, p = 0.014). On immunohistochemistry, the expression of alpha smooth muscle actin was lower in the treated vs. control group.ConclusionApposition of a self-assembling peptide matrix immediately after a circumferential esophageal ESD reduced by 67% the occurrence of a stricture at day 14, by promoting reepithelialization of the resected area.

Randomised in situ clinical trial investigating self-assembling peptide matrix P11-4 in the prevention of artificial caries lesions

The aim was to investigate the ability of self-assembling Peptide P11-4 Matrix (SAPM) to remineralize artificial initial caries lesions compared to the use of fluoride varnish. Volunteers were recruited for this randomised, cross-over in situ trial. Bovine specimens, half including orthodontic brackets, were recessed on the buccal aspects of mandibular appliances. Specimens included internal sound enamel control, a demineralised control and a part exposed during the in situ phase. Each phase lasted four weeks, followed by a one-week washout. Treatment groups were: A: negative control, no treatment,B: positive control, 22,600 ppm fluoride varnish,C: test group, 1,000 ppm SAPM. Laser fluorescence values (LF) were measured before/after demineralisation, and after the in situ period. Micro-CT analysis was used to assess mineral changes within the specimens after the in situ phase. In specimens without brackets, ΔLF values after in situ phase were: A: +5.28, B: +0.85, C: −2.89. Corresponding ΔLF for specimens with brackets were: A: +5.77, B: +1.30, C: −3.15. LF-values between groups significantly differed from each other (p < 0.0001) after the in situ phase. Micro-CT analysis yielded no significant difference among groups for specimens without brackets. For specimens with brackets, the test group showed significantly more remineralisation than the negative (p = 0.01) and positive control (p = 0.003). Within the limitations of the study, SAPM showed prevention of caries and remineralisation of enamel around orthodontic brackets.

Self-assembling peptide matrix for treatment of dentin hypersensitivity: A randomized controlled clinical trial.

Patient-reported dentin hypersensitivity [DHS] pain is a common finding linked with periodontal disease. This pilot clinical study investigates a novel therapeutic regimen using self-assembling peptide matrix [SAPM] gel (test) compared with use of an 8% arginine and calcium carbonate [ACC] toothpaste (control) for treatment of DHS. A total of 50 patients with history of supportive periodontal therapy were enrolled in this prospective, randomized monocentric clinical study, of which 45 (test: n=22; control: n=23) fulfilled all the study visits. Test group patients performed ex-office application of SAPM gel over 1week, while control group patients performed ex-office application of ACC toothpaste over 90 days. DHS was assessed in office by Visual Analog Scale [VAS], and patient's perception of pain relief was evaluated by questionnaire. In support of the clinical data, scanning electron microscopy images were recorded to investigate tubule occlusion of both control and test product. Both SAPM and ACC significantly reduced DHS in patients throughout the study, with the patient questionnaire indicating higher patient satisfaction at the earlier time points for the test group. Both SAPM gel and ACC toothpaste were successful in providing relief from DHS and showed similar outcomes on VAS and verbal response scale (VRS) throughout the study period of 90 days. The new therapeutic regimen using SAPM resulted in higher patient satisfaction at day 7, as indicated by the patient questionnaire and the higher number of pain-free patients at day 7 and day 90. This is a pilot study describing a novel therapy for DHS.

Self-assembling peptide matrix for the prevention of esophageal stricture after endoscopic resection: a randomized controlled trial in a porcine model.

Esophageal stricture formation after extensive endoscopic resection remains a major limitation of endoscopic therapy for early esophageal neoplasia. This study assessed a recently developed self-assembling peptide (SAP) matrix as a wound dressing after endoscopic resection for the prevention of esophageal stricture. Ten pigs were randomly assigned to the SAP or the control group after undergoing a 5-cm-long circumferential endoscopic submucosal dissection of the lower esophagus. Esophageal diameter on endoscopy and esophagogram, weight variation, and histological measurements of fibrosis, granulation tissue, and neoepithelium were assessed in each animal. The rate of esophageal stricture at day 14 was 40% in the SAP-treated group versus 100% in the control group (P = 0.2). Median interquartile range (IQR) esophageal diameter at day 14 was 8 mm (2.5-9) in the SAP-treated group versus 4 mm (3-4) in the control group (P = 0.13). The median (IQR) stricture indexes on esophagograms at day 14 were 0.32 (0.14-0.48) and 0.26 (0.14-0.33) in the SAP-treated and control groups, respectively (P = 0.42). Median (IQR) weight variation during the study was +0.2 (-7.4; +1.8) and -3.8 (-5.4; +0.6) in the SAP-treated and control groups, respectively (P = 0.9). Fibrosis, granulation tissue, and neoepithelium were not significantly different between the groups. The application of SAP matrix on esophageal wounds after a circumferential endoscopic submucosal dissection delayed the onset of esophageal stricture in a porcine model.

Three‐dimensional self‐assembling peptide matrix enhances the formation of embryoid bodies and their neuronal differentiation

We have tailored the properties of a self-assembling peptide (SAP) matrix to direct embryonic stem cells towards neuronal differentiation by adopting a three-dimensional (3D) culture, matching mechanical strength with that of neural tissue, and incorporating fixed laminin-derived pentapeptide signals (IKVAV). We report here that such a matrix alone can induce mouse embryonic stem (ES) cells to first develop into embryoid body (EB) and increase their propensity for subsequent neuronal differentiation. Embryoid bodies were observed by day 5 of culture in SAP matrix. βIII-tubulin as an early neuronal commitment marker was more prominently detected in cells cultured in the matrix containing IKVAV signals. Interestingly, ES-derived cells did not display distinct neuron morphology within the 3D culture; however, 55 ± 10% of those cells within IKVAV conjugated matrix and 38 ± 6% of those within base matrix displayed higher potential towards neuronal differentiation after 7 days. When retrieved and recultured on a tissue culture plate, they exhibited extended neurite outgrowths and networks in the absence of any additional neuronal differentiation growth factor. The up-regulated expression of neuronal development markers (MAP2 and MeCP2) and the down-regulation of glial marker (GFAP) support that further neuronal differentiation takes place upon reculture. The results showed that an artificial matrix composed of designer SAPs could prompt the formation of EB and provides the cues favoring neuronal differentiation of ES cells.

A self-assembling peptide matrix used to control stiffness and binding site density supports the formation of microvascular networks in three dimensions

A three-dimensional (3-D) cell culture system that allows control of both substrate stiffness and integrin binding density was created and characterized. This system consisted of two self-assembling peptide (SAP) sequences that were mixed in different ratios to achieve the desired gel stiffness and adhesiveness. The specific peptides used were KFE ((acetyl)-FKFEFKFE-CONH2), which has previously been reported not to support cell adhesion or MVN formation, and KFE-RGD ((acetyl)-GRGDSP-GG-FKFEFKFE-CONH2), which is a similar sequence that incorporates the RGD integrin binding site. Storage modulus for these gels ranged from ∼60 to 6000Pa, depending on their composition and concentration. Atomic force microscopy revealed ECM-like fiber microarchitecture of gels consisting of both pure KFE and pure KFE-RGD as well as mixtures of the two peptides. This system was used to study the contributions of both matrix stiffness and adhesiveness on microvascular network (MVN) formation of endothelial cells and the morphology of human mesenchymal stem cells (hMSC). When endothelial cells were encapsulated within 3-D gel matrices without binding sites, little cell elongation and no network formation occurred, regardless of the stiffness. In contrast, matrices containing the RGD binding site facilitated robust MVN formation, and the extent of this MVN formation was inversely proportional to matrix stiffness. Compared with a matrix of the same stiffness with no binding sites, a matrix containing RGD-functionalized peptides resulted in a ∼2.5-fold increase in the average length of network structure, which was used as a quantitative measure of MVN formation. Matrices with hMSC facilitated an increased number and length of cellular projections at higher stiffness when RGD was present, but induced a round morphology at every stiffness when RGD was absent. Taken together, these results demonstrate the ability to control both substrate stiffness and binding site density within 3-D cell-populated gels and reveal an important role for both stiffness and adhesion on cellular behavior that is cell-type specific.

Development of a three-dimensional bone-like construct in a soft self-assembling peptide matrix.

This work describes the development of a three-dimensional (3D) model of osteogenesis using mouse preosteoblastic MC3T3-E1 cells and a soft synthetic matrix made out of self-assembling peptide nanofibers. By adjusting the matrix stiffness to very low values (around 120 Pa), cells were found to migrate within the matrix, interact forming a cell-cell network, and create a contracted and stiffer structure. Interestingly, during this process, cells spontaneously upregulate the expression of bone-related proteins such as collagen type I, bone sialoprotein, and osteocalcin, indicating that the 3D environment enhances their osteogenic potential. However, unlike MC3T3-E1 cultures in 2D, the addition of dexamethasone is required to acquire a final mature phenotype characterized by features such as matrix mineralization. Moreover, a slight increase in the hydrogel stiffness (threefold) or the addition of a cell contractility inhibitor (Rho kinase inhibitor) abrogates cell elongation, migration, and 3D culture contraction. However, this mechanical inhibition does not seem to noticeably affect the osteogenic process, at least at early culture times. This 3D bone model intends to emphasize cell-cell interactions, which have a critical role during tissue formation, by using a compliant unrestricted synthetic matrix.

Factorial analysis of adaptable properties of self-assembling peptide matrix on cellular proliferation and neuronal differentiation of pluripotent embryonic carcinoma

An integrative and quantitative approach for systematically studying the effects of changing the matrix environment on pluripotent cell viability and neuronal differentiation was demonstrated. This approach, based on factorial analysis and a self-assembling peptide (SAP) matrix, was exemplified using P19 as a pluripotent cell model. In a two-level, three-factor factorial design of experiments, three niche factors, namely, culture dimensionality, fixed biochemical signal and mechanical stiffness, were simultaneously investigated. We found that cell growth was slowed in matrices containing IKVAV epitopes on the SAP constructs, and neuronal differentiation was promoted synergistically by culturing in a three-dimensional matrix and in the presence of IKVAV. Variation of the storage modulus from around 262 Pa to 672 Pa had no significant effect on either viability or differentiation. This approach should be applicable to studying how niche properties that are tunable using SAPs affect the behavior of pluripotent cells in general, thus generating guidelines for constructing artificial matrices. From the Clinical EditorIn this basic science study, an integrative and quantitative approach to study the effects of matrix environment on pluripotent cell viability and neuronal differentiation is demonstrated. Approaches, like the one described in this paper, are applicable to studying how self assembling peptides affect the behavior of pluripotent cells in general.