A New Drug Delivery System - Silk Fibroin Film Loaded or Not With Insulin on Palatal Mucosa Wound Healing

Study Overview
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Brief Summary
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The aim of the present study is to evaluate using clinical, patient-centered, immunological, microbiological, and histological parameters, the effect of silk fibroin films loaded or not with insulin in the repair of palatal mucosa open wounds.

Detailed Description
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There are several types of periodontal and peri-implant soft tissue defects that require surgical treatment to reestablishment function and aesthetics. Therefore, surgical procedures for the reconstruction of the gingival and peri-implant tissues are routinely performed. However, these procedures do not always have predictable outcomes, and problems with the wound healing process can occur, which can impair the outcomes. To overcome this problem, new materials, drugs, and devices have been used to improve the results of surgical procedures. The present study is a controlled clinical trial that will include seventy-five patients with an indication of anterior maxillary tooth extraction for ridge preservation. The ridge preservation will be performed and a free gingival graft harvest from the palatal mucosa will be used to seal the socket entrance. Thereafter, the palatal wound will be randomly assigned into 3 groups: Control Group (C; n=25): open wound on palatal mucosa that will receive no treatment. Blank Film Group (BF; n=25): open wound on palatal mucosa that will receive silk fibroin film as dressing. Insulin-loaded film (IF; n=25): open wound on palatal mucosa that will receive an insulin-loaded silk fibroin film as a delivery system. Clinical, immunological, histological, and microbiome parameters will be analyzed.

Official Title
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A New Drug Delivery System - Silk Fibroin Film Loaded or Not With Insulin on Palatal Mucosa Wound Healing: in Vitro Study and a Randomized Clinical Trial.

Conditions
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Wound Healing, Insulin, Palate; Wound

Intervention / Treatment
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* Procedure: Palatal Wound
* Device: Palatal Wound treated with Silk Fibroin Film
* Device: Palatal Wound treated with Insulin-loaded Silk Fibroin Film


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with at least 18 years, systemically healthy, with good oral hygiene, assessed by plaque index and gingival index less than 25% (Ainamo, Bay, 1975); Patients with no morphological or pathological conditions on the palatine donor area; Patients who present indication for extraction and ridge preservation; The tooth included in the study, as well as, the adjacent teeth do not present loss of periodontal insertion; Patients who agreed to and sign the formal consent to participate in the study after receiving an explanation of risks and benefits from an individual who was not a member of the present study (Resolution no. 118 - May, 2012, and Ethics and Code of Professional Conduct in Dentistry - 118/12). Exclusion Criteria: Patients with systemic problems (cardiovascular, blood dyscrasias, immunodeficiency, and diabetes, among others) that will contraindicate the surgical procedure; Patients taking medications known to interfere with the wound healing process or that contraindicate the surgical procedure; Smokers patients; Pregnant or lactating patients; Patients who had had periodontal surgery on the study area; Patients who presents opportunistic oral lesions, mainly colonized the palate region; Use of dental prosthesis with palatal cover; Thin palatal mucosa ( 2.0mm).

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: This is a double-blind, parallel, superiority, randomized clinical trial with 3 months of follow-up.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Control Group (CG)<br>The palatal wound area will not receive any treatment | Procedure: Palatal Wound<br>* With the goal to harvest the free gingival graft (FGG), an 8mm diameter scalpel will be used to ensure standardized wounds. Thereafter, a 2-mm thick FGG will be removed. The wound area will receive 4.0 silk sutures.<br>|
| Experimental: Blank Film Group (BF)<br>The palatal wound area will receive silk fibroin film as a dressing | Procedure: Palatal Wound<br>* With the goal to harvest the free gingival graft (FGG), an 8mm diameter scalpel will be used to ensure standardized wounds. Thereafter, a 2-mm thick FGG will be removed. The wound area will receive 4.0 silk sutures.<br>Device: Palatal Wound treated with Silk Fibroin Film<br>* With the goal to harvest the free gingival graft (FGG), an 8mm diameter scalpel will be used to ensure standardized wounds. Thereafter, a 2-mm thick FGG will be removed. The wound area will receive a silk fibroin film and 4.0 silk sutures.<br>|
| Experimental: Insulin-loaded film (IF)<br>The palatal wound area will receive an insulin-loaded silk fibroin film as a drug delivery system | Procedure: Palatal Wound<br>* With the goal to harvest the free gingival graft (FGG), an 8mm diameter scalpel will be used to ensure standardized wounds. Thereafter, a 2-mm thick FGG will be removed. The wound area will receive 4.0 silk sutures.<br>Device: Palatal Wound treated with Insulin-loaded Silk Fibroin Film<br>* With the goal to harvest the free gingival graft (FGG), an 8mm diameter scalpel will be used to ensure standardized wounds. Thereafter, a 2-mm thick FGG will be removed. The wound area will receive a silk fibroin film loaded with insulin and 4.0 silk sutures.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the Remaining wound healing (RWA) | Photographs will be taken from palatal wound with brightness, distance, and angle standardized. A scale will be placed in the palate as a reference to measure the area. These photographs will be exported to an image software (Image J - NIH, Bethesda, USA), and the wound area will be measured in square millimeters (Dias et al., 2015). | 90 days. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tissue Thickness (TT) | Tissue thickness of palatine masticatory mucosa will be assessed by a Cone Beam Computed Tomographic (CBCT). In order to standardize the volume measures, the FGG harvested stent, made of 1 mm thick rigid acrylic plates in vacuum plasticizer with radiopaque material, will be used by the patient at the time of the CBCT image acquisition. | 90 days | 
| Epithelialization (E) | Wound will be colored with Replack (Dentisply - York, Pensilvânia - USA) and quantity measured by Image J program. Then, with the total area of the wound, the epithelization % will be calculated (Ozcelik et al. 2008). | 90 days | 
| Early- wound healing index (EWHI) | According to Fickl et al. 2014 any modification in wound healing will be evaluated in five different degrees: Complete wound closure with an absence of fibrin on the palate; Complete wound closure with the presence of a fibrin line on palate; Complete wound closure with the presence of a clot with fibrin on palate Incomplete wound closure with partial tissue necrosis on palate; Incomplete wound closure with total tissue necrosis on palate | 14 days | 
| Tissue Edema (TE) | Tissue edema will be evaluated with the score: 1 = absent; 2 = slight; 3 = moderate; or 4 = severe (Sanz-Moliner et, 2013). | 7 days | 
| Oral Health Impact Profile | Will be evaluated from a questionnaire with 14 questions based on 7 domains: functional limitations, physical pain, psychological discomfort, physical disability, psychological deficiency and social deficiency. The patient should respond to the questions within 14 days after the surgical procedure, performing a postoperative diary. For each question an answer must be given, represented in numbers, being: 0- Never; 1- Almost never; 2-Occasionally; 3-Quite frequent; 4-Very common; 5-I do not know (Tonetti MS et al. 2017) | 14 days | 
| Number of analgesics | Number of analgesics used during 14 days after the procedure will be reported at the same postoperative diary (Tonetti et al. 2017). | 14 days | 
| Patient Discomfort | By a visual analogic scale (VAS) of 100 mm to assess discomfort, patients will report pain diary during the 14 days after surgery. Scale extremes will be no pain to extreme. (Tonetti et al. 2017). | 14 days | 
| Qualitative somatosensory testing (QualST) | This analysis will evaluate somatosensorial profiles and pain conditions. For this, different stimulus will be performed on the wound and the following tests will be applied: (1) Touch stimulus will be applied with a swab by a single application for 1-2 sec in the wound; (2) Cold stimulus will be applied by a stainless steel dental spatula (kept cool in ice water, approximately 0 °C) with wound direct contact during 1-2 sec; (3) The pinprick stimulus will be performed with a periodontal probe with moderate force on the wound area for 1-2 s (Baad-Hansen et al, 2013) Patient will report hypersensitivity, hyposensitivity, or normosensitivity to touch, cold and painful stimulus. | 14 days | 
| Immunologic Analysis | With the goal to obtain baseline data for this parameter, crevicular gingival fluid from the gingival area next to the donor area will be collected previous surgery. An absorbent paper (PerioPaper, Oraflow, Plainview, NY, EUA) will be placed at wound edges without pressure during 40s. Collects with blood contamination will be discarded. Samples will be stored into a sterilized Eppendorf containing 100 μL Phosphate Buffer Saline 0.05% Tween 2 (PBS) at - 80 C. Growth factors (VEGF and EGF), chemokines (MIP-1α, MCP-1α), and cytokines (IL1β, IL6, IL10, TNFα) levels will be determinate by the multiplex assay. Moreover, MMP-2, MMP-9, TIMP-1, TIMP-2 will be measured by the same commercial human commercial kit. | 7 days | 
| Histological Analysis | CTG will be harvested from the palatal area, the same area that received FGG protocol previously, using the same harvesting stent, during implant therapy. After CTG be harvested, a 2-mm thick will be removed from the graft (Azar et al., 2019) to perform biopsy analysis aiming to observe histological changes during healing process by previously use of silk fibroin film, charged or not with insulin, and spontaneous repair. The specimens will be immersed in 10% formalin for histological analysis which will be stained with hematoxylin-eosin and Masson's trichrome. | 180 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Wound Healing, Drug Delivery System, Insulin, Fibroin