Release Kinetics in PRF Versus GEM21S With and Without Bone Substitutes: An In Vitro Analysis

November 24, 2025 updated by: Maria L. Geisinger, DDS, MS, University of Alabama at Birmingham

Growth Factor Availability and Release Kinetics in PRF Versus GEM21S With and Without Bone Substitutes: An In Vitro Analysis

This study is seeking to evaluate that platelet-derived growth factor-BB (PDGF-BB) is a proven wound healing and osteogenic protein that plays a critical role in wound healing and previous research has demonstrated a non-linear response where higher dosages produced less effect. As Platelet Rich Fibrin (PRF) contains numerous platelets, it contains PDGF-BB, but at levels lower than in the commercially available product and with inter-individual variation, GEM21S. To achieve both ideal handling and achieve ideal levels of PDGF-BB, there is a rationale to add GEM 21S recombinant human platelet-derived growth factor-BB (rhPDGF) to a bone graft prior to making "sticky bone".

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Innovations in biomedicine and recombinant protein technology show promising advances for the regeneration of advanced alveolar defects. Recombinant growth factors and biologics encourage minimally invasive procedures with improved clinical outcomes/healing times in complex oral surgery procedures. PDGF-BB is a growth factor that is known to be a potent mitogen and chemotactic agent for cells important in wound healing and bone regeneration. PDGF-BB is also a strong angiogenic agent. These properties provide a solid biological mechanism of action and rationale for the widespread use of rhPDGF-BB in dental and orthopedic surgery, as well as in the treatment of difficult soft tissue wounds. Practically, two sources of supra-physiologic levels PDGF-BB are currently available for use in dental hard and soft tissue defects: 1) Platelet concentrates (PRF/PRF); and 2) GEM 21S, which contains recombinant human PDGF-BB (rhPDGF-BB). Platelet rich plasma was first introduced to dentistry in 1998 by Robert Marx. Since then, other autologous products have evolved. Platelet rich fibrin (PRF) is one that is used daily in various clinical scenarios, including guided bone regeneration. The rationale for its use is due to the supraphysiologic concentration of growth factors (ie PDGF-BB) and cells to enhance would healing. Clinicians also frequently incorporate PRF to bone grating materials to improve handling properties of the graft material, also referred to as "sticky bone". However, the literature varies greatly on the believed mechanism of action and the therapeutic benefits claimed by their supporters. The rationale for this proposed study that PDGF-BB is a proven wound healing and osteogenic protein, but there are clinically insignificant amounts of PDGF-BB in PRF. Therefore, there is a rationale to add GEM 21S (rhPDGF) to a bone graft prior to making "sticky bone" with PRF. This would provide clinicians the benefits of a clinically proven and consistent dose of rhPDGF to improve wound healing and bone formation in conjunction with the benefits of the improved handling (i.e. sticky bone) from the addition of the PRF.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
5

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Maria Geisinger, DDS,MS
  • Phone Number: 205-934-4984
  • Email: miagdds@uab.edu

Study Contact Backup

  • Name: Sarah Startley, DMD
  • Phone Number: 205-975-8711
  • Email: ss1971@uab.edu

Study Locations

  • United States
    • Alabama
      • Birmingham, Alabama, United States, 35294-0007
        • University of Alabama at Birmingham

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 99 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Probability Sample

Study Population

Participants must be at least 18 years old with demonstrated ability to understand and consent to the proposed study procedures. Subjects treated in the UAB School of Dentistry Periodontal Clinic and scheduled for procedures using platelet rich fibrin (PRF) were performed.

Description

Inclusion Criteria:

  • English speaking
  • At least 18 years old
  • Able to read and understand informed consent document
  • Systemically healthy, non-smoker, no medications

Exclusion Criteria:

  • Non-English speaking
  • Less than 18 years old
  • Smokers/tobacco users (>10 cigarettes/day)
  • Patients with systemic pathologies or conditions contraindicating oral surgical procedures or adversely affecting healing

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Amount of PDGF-BB in PRF preparation vs. GEM21
The release kinetics of PDGF-BB will be assessed for one PRF preparation from each of the six individual participants and one GEM 21S sample. The quantification will be performed at 60 minutes, 8 hours, 1 day, 3 days, and 10 days. The samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At each desired time point assessment, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol.
Biological: Amount of PDGF-BB in PRF preparation vs. GEM21
The quantification will be performed at 60 minutes, 8 hours, 1 day, 3 days, and 10 days. The samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At each desired time point assessment, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol.
PDGF-BB available in PRF + bone substitutes vs. rhPDGF-BB+ bone substitutes
Growth factor release assessments will be made to determine the PDGF-BB present in the six prepared samples of the following: 1) PRF + mineralized freeze-dried corticocancellous allograft, 2) PRF + xenograft, and 3) PRF + B-TCP. Assessments will also be made for one sample of each of the following: 1) rhPDGF-BB + freeze-dried bone allograft, 2) rhPDGF-BB + xenograft, and 3) rhPDGF-BB+ B-TCP preparation. This assessment will be made at 60 minutes following the incorporation of the bone graft materials. During this time period, the samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At 60 minutes after preparation, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol.
Biological: Amount of PDGF-BB available in PRF + bone substitutes vs. rhPDGF-BB+ bone substitutes following preparation
Growth factor release assessments will be made to determine the PDGF-BB present in the six prepared samples of the following: 1) PRF + mineralized freeze-dried corticocancellous allograft, 2) PRF + xenograft, and 3) PRF + B-TCP. Assessments will also be made for one sample of each of the following: 1) rhPDGF-BB + freeze-dried bone allograft, 2) rhPDGF-BB + xenograft, and 3) rhPDGF-BB+ B-TCP preparation. This assessment will be made at 60 minutes following the incorporation of the bone graft materials. During this time period, the samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At 60 minutes after preparation, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol.
: Release kinetics of PDGF-BB in PRF + bone substitutes vs. rhPDGF-BB + bone substitutes
The release kinetics of PDGF-BB will be assessed for six preparations of each of following: 1) PRF+ mineralized freeze-dried corticocancellous allograft, 2) PRF + bone xenograft, and 3) PRF + B-TCP. The release kinetics of PDGF-BB will also be assessed for one preparations of each of following: 1) rhPDGF-BB + mineralized freeze-dried corticocancellous allograft, 2) rhPDGF-BB + bone xenograft, 3) rhPDGF-BB + TCP. The quantification will be performed at 60 minutes, 8 hours, 1 day, 3 days, and 10 days. The samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At each desired time point assessment, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol.
Biological: Release kinetics of PDGF-BB in PRF + bone substitutes vs. rhPDGF-BB + bone substitutes
The release kinetics of PDGF-BB will be assessed for six preparations of each of following: 1) PRF+ mineralized freeze-dried corticocancellous allograft, 2) PRF + bone xenograft, and 3) PRF + B-TCP. The release kinetics of PDGF-BB will also be assessed for one preparations of each of following: 1) rhPDGF-BB + mineralized freeze-dried corticocancellous allograft, 2) rhPDGF-BB + bone xenograft, 3) rhPDGF-BB + TCP. The quantification will be performed at 60 minutes, 8 hours, 1 day, 3 days, and 10 days. The samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At each desired time point assessment, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol.
Release kinetics of PDGF-BB in rhPDGF-BB + PRF + bone substitutes
The quantification will be performed at 60 minutes, 8 hours, 1 day, 3 days, and 10 days. The samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At each desired time point assessment, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol. The samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At each desired time point assessment, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol.
Biological: Release kinetics of PDGF-BB in rhPDGF-BB + PRF + bone substitutes
The quantification will be performed at 60 minutes, 8 hours, 1 day, 3 days, and 10 days. The samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At each desired time point assessment, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol. The samples will each be placed in a cell incubator at 37°C to allow for growth factor release into a phosphate-buffered saline. At each desired time point assessment, 2 ml of the sample will be collected, frozen, and replaced with 2 ml of additional phosphate-buffered saline. The protein quantification will be carried out using ELISA assay according to manufacturer's protocol.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
To quantify any difference in the release of PDGF-BB after application to rhPDGF-BB and PRF
Time Frame: From baseline to 10 days
The quantities of PDGF-BB statistical analysis using a two-way analysis of variance for the proliferation assay with Bonferroni test.
From baseline to 10 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Alabama at Birmingham

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 31, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 31, 2023

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 6, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 6, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 16, 2021

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 2, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 24, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB-300005971
  • UAB-Perio (Other Identifier: University of Alabama at Birmingham)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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