Platelet-Rich Plasma

Platelet-rich plasma (PRP) is an autologous blood-derived concentrate increasingly utilized in regenerative medicine for its ability to accelerate healing and tissue repair. PRP is broadly classified by leukocyte content, fibrin architecture, and platelet concentration, with classification systems developed to standardize characterization. Preparation methods, including single- or double-spin centrifugation and buffy coat techniques, influence the final composition of PRP, determining the relative proportions of platelets, leukocytes, plasma proteins, and extracellular vesicles. These components act synergistically, with platelets releasing growth factors (e.g., VEGF, PDGF, TGF-β) that stimulate angiogenesis and matrix synthesis, leukocytes providing immunomodulation, plasma proteins facilitating scaffolding, and exosomes regulating intercellular signaling. Mechanistically, PRP enhances tissue repair through four key pathways: platelet adhesion molecules promote hemostasis and cell recruitment; immunomodulation reduces pro-inflammatory cytokines and favors M2 macrophage polarization; angiogenesis supports vascular remodeling and nutrient delivery; and serotonin-mediated pathways contribute to analgesia. These processes establish a regenerative microenvironment that supports both structural repair and functional recovery. Clinically, PRP has been applied across multiple specialties. In orthopedics, it promotes tendon, cartilage, and bone healing in conditions such as tendinopathy and osteoarthritis. In dermatology, PRP enhances skin rejuvenation, scar remodeling, and hair restoration. Gynecology has adopted PRP for ovarian rejuvenation, endometrial repair, and vulvovaginal atrophy. In dentistry and oral surgery, PRP accelerates wound closure and osseointegration, while chronic wound care benefits from its angiogenic and anti-inflammatory effects. PRP has also favored gingival recession coverage, regeneration of intrabony periodontal defects, and sinus grafting. Although preparation heterogeneity remains a challenge, PRP offers a versatile, biologically active therapy with expanding clinical utility.

Rational: Spinal cord injury (SCI) is among the most devastating conditions affecting the central nervous system. Nerve regeneration and vascular regeneration are two important strategies for SCI. While platelet-rich plasma (PRP) gel is a bio-hydrogel enriched with a large number of growth factors. It has an excellent ability to promote blood vessel regeneration, but its role in nerve repair needs to be further enhanced. In addition, its weak mechanical properties and rapid release of components have limited its efficacy. Method: In this study, we cleverly applied the dual effects of activation and cross-linking of calcium ions to construct a novel PRP/ sodium alginate (Alg)/ gelatin methacrylate (GelMA) triple-networked hydrogel and enhanced the hydrogel's function in promoting nerve regeneration using brain-derived neurotrophic factor (BDNF). Results: In vitro experiments, we verified the biomimetic, injectable, biodegradable, biocompatible, vascular regenerative and neural regenerative properties of the neural-enhancing triple-network hydrogel by involving endothelial cells and neural stem cells (NSCs). When implanted into SCI rats, this hydrogel significantly improved its motor function. It promotes neuronal differentiation, inhibits astrocyte differentiation, supports axonal regeneration, and enhances the migration of endogenous NSCs and vascular regeneration. In addition, this hydrogel may facilitate neurogenesis and angiogenesis via activating the PI3K/AKT/mTOR signaling pathway. Conclusions: The neural regeneration-enhanced triple-network hydrogel we developed has excellent dual biological functions of neural regeneration and angiogenesis, and it is a straightforward, viable, and promising therapeutic strategy for SCI regeneration.

The objective of the study was to compare the treatment outcomes of periodontal furcation defects by using platelet-rich fibrin (PRF) with other commonly utilized modalities. The eligibility criteria comprised randomized controlled trials (RCTs) comparing the clinical outcomes of PRF with those of other modalities for the treatment of furcation defects. Studies were classified into 11 categories in 3 different groups as follows: Group I (addition of PRF): (1) open flap debridement (OFD) alone versus OFD/PRF, (2) OFD/bone graft (OFD/BG) versus OFD/BG/PRF; Group II (comparative studies to PRF): (3) OFD/BG versus OFD/PRF, (4) OFD/collagen membrane versus OFD/PRF, (5) OFD/PRP versus OFD/PRF, (6) OFD/rhBMP2 versus OFD/PRF; and Group III (addition of biomaterial/biomolecule to PRF): OFD/PRF versus … (7) OFD/PRF/BG, (8) OFD/PRF/amniotic membrane (AM), (9) OFD/PRF/metformin, (10) OFD/PRF/bisphosphonates, (11) OFD/PRF/statins. Weighted means and forest plots were calculated for the reduction of probing pocket depth (PPD), gain of vertical and horizontal clinical attachment levels (VCAL and HCAL), gain in vertical and horizontal bone levels (VBL, HBL), and radiographic bone fill (RBF). From 45 articles identified, 21 RCTs reporting on class II furcations were included. The use of OFD/PRF and OFD/BG/PRF statistically significantly reduced PPD and improved VCAL and HCAL when compared to OFD or OFD/BG, respectively. The comparison between OFD/PRF alone versus OFD/BG, OFD/CM, OFD/PRP, or OFD/rhBMP2 led to similar outcomes for all investigated parameters, including a reduction in PPD, VCAL/HCAL gain, and RBF. The additional incorporation of a BG to OFD/PRF only mildly improved outcomes, whereas the addition of AM improved clinical outcomes. The addition of small biomolecules such as metformin, bisphosphonates, or statins all led to significant improvements in PPD, VCAL, and HCAL when compared to OFD/PRF alone. Noteworthy, a very high heterogeneity was found in the investigated studies. The use of PRF significantly improved clinical outcomes in class II furcation defects when compared to OFD alone, with similar levels being observed between OFD/PRF and/or OFD/BG, OFD/CM, OFD/PRP, or OFD/rhBMP2. Future research geared toward better understanding potential ways to enhance the regenerative properties of PRF with various small biomolecules may prove valuable for future clinical applications. Future histological research investigating PRF in human furcation defects is largely needed. The use of PRF in conjunction with OFD statistically significantly improved PPD, VCAL, and HCAL values, yielding comparable outcomes to commonly used biomaterials. The combination of PRF to bone grafts or the addition of small biomolecules may offer additional clinical benefits, thus warranting future investigation.

Macrophage-driven oxidative stress and chronic inflammation play pivotal roles in the progression of atherosclerosis. Given the overactivation of poly (ADP-ribose) polymerase (PARP) in atherosclerosis, PARP inhibitors have potential therapeutic potential, but their efficacy is limited due to poor in vivo targeting. Platelet-rich plasma-derived extracellular vesicles (PEVs), which inherently target inflammatory sites and mitigate oxidative stress, offer a promising delivery platform. Here, we developed NGPPEVs, a nanoplatform that employs PEVs to deliver niraparib, a PARP inhibitor, followed by encapsulation of Ca(HCO₃)₂ to generate gas within cells, thereby combining targeted therapy with ultrasound imaging capabilities. In vitro, NGPPEVs significantly scavenged intracellular reactive oxygen species (ROS) and suppressed pathways related to oxidative stress and cholesterol metabolism. Mechanistically, NGPPEVs suppressed foam cell formation by inhibiting the PARP1-IL-6-CD36 axis, leading to significant downregulation of the key scavenger receptor CD36. In apolipoprotein E-deficient mice fed a high-fat high-cholesterol diet, NGPPEVs demonstrated superior therapeutic efficacy, effectively reducing atherosclerotic plaque area and enhancing plaque stability. Collectively, NGPPEVs have great potential in the precise diagnosis and treatment of atherosclerosis.