China
Africa
Explore chapters and articles related to this topic
Nanopharmaceuticals in Alveolar Bone and Periodontal Regeneration
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Mark A. Reynolds, Zeqing Zhao, Michael D. Weir, Tao Ma, Jin Liu, Hockin H. K. Xu, Abraham Schneider
Stem cells and tissue engineering approaches are highly attractive for alveolar bone and periodontal regeneration (Shimauchi et al. 2013). Biomaterials, active agents (e.g., growth factors), and stem cells represent important strategies in regenerative medicine. Nanotechnology, such as nanostructured biomaterials, have shown promise in providing excellent capabilities of being biocompatible, biodegradable and osteoinductive, in order to enhance stem and mesenchymal cell attachment, proliferation, and differentiation (Bottino et al. 2011; Liu et al. 2018). In addition, bioactive factors, other proteins, and pharmaceuticals can be added into biomaterials (Meirelles et al. 2010). For example, platelet-rich growth factor (PDGF), bone morphogenetic proteins (BMPs), metformin, human platelet lysate (HPL), and enamel matrix derivatives have demonstrated potential to promote periodontal wound healing and regeneration (Lyngstadaas et al. 2009).
Synergistic Antimicrobial Activity of Silver and Chitosan
Published in Huiliang Cao, Silver Nanoparticles for Antibacterial Devices, 2017
Sulbha K. Sharma, Gitika Kharkwal, Ying-Ying Huang, Michael R. Hamblin
Wound dressings made from either hydroxypropylmethyl cellulose or chitosan glutamate (CS-glu) containing silver sulfadiazine encapsulated in solid lipid nanoparticles were investigated for applications in tissue repair (Sandri et al. 2013). These polymers were chosen to obtain a sponge matrix with suitable elasticity and softness and, moreover, with good bioadhesive properties to skin lesions, and moreover, platelet lysate (a source of growth factors) was added to stimulate healing. Dressings based on chitosan glutamate showed the best antimicrobial activity both with and without platelet lysate. Nanoparticle-based materials are often used as coatings applied to biomaterial devices on order to enhance sterility against a variety of microbes. In one study, silk fibres (SF) were coated with chitosan impregnated with AgNP (Ag-C-SF). The modified fibres also showed good antimicrobial activity and improved thermal stability (Karthikeyan et al. 2011). Fabrication of new chitosan-based composite sponges containing AgNP for wound dressings showed that the new AgNP-loaded chitosan-based composite sponges possessed not only bacteriostatic but also bactericidal activity against these tested bacteria (Li et al. 2011a).
Drug treatment of varicose veins, venous edema, and ulcers
Published in Peter Gloviczki, Michael C. Dalsing, Bo Eklöf, Fedor Lurie, Thomas W. Wakefield, Monika L. Gloviczki, Handbook of Venous and Lymphatic Disorders, 2017
A range of drugs has been used in the management of leg ulcers. These may be given systemically or applied topically. In addition, a wide range of wound dressings has become available, some of which have “active” properties which might promote wound healing. Honey has been applied to leg ulcers as a wound dressing in the expectation that this will lead to more rapid healing. A recent Cochrane review has found that there is very limited evidence of efficacy for this treatment amongst low-quality studies.7 A Cochrane review assessed the published data in 42 clinical trials in which hydrocolloid, foam, alginate, and hydrogel dressings were assessed.8 The authors concluded that there was no evidence that any of these approaches accelerated wound healing when these were applied beneath compression. A further review has investigated published data concerning wound dressing and other topical applications.9 The authors considered 68 studies for inclusion in their analysis and eliminated all but 20, excluding the remainder on the basis of poor study design. Eight studies addressed the use of wound dressings, but none showed conclusive advantage of any other dressing in accelerating wound healing. A further seven studies addressed the subject of topical growth factor application. The list of compounds applied topically included platelet lysate, keratinocyte lysate, vasoactive intestinal peptide, granulocyte colony-stimulating factor (G-CSF), and becaplemin. Of these, only G-CSF improved ulcer healing significantly, and these data were confined to one clinical trial. In five studies, human skin equivalents were investigated. These included Dermagraf, cultured keratinocytes, Apligraf, Epidex, and cultured epidermal allografts. Amongst these, evidence of improved healing was found in only one, a study of the use of Apligraf involving 275 patients.
Platelet lysate and tendon healing: comparative analysis of autologous frozen-thawed PRP and ketorolac tromethamine in the treatment of patients with rotator cuff tendinopathy
Published in Growth Factors, 2022
Raha Markazi, Mohammad Sadegh Soltani-Zangbar, Majid Zamani, Shadi Eghbal-Fard, Roza Motavalli, Amin Kamrani, Sanam Dolati, Majid Ahmadi, Leili Aghebati-Maleki, Amir Mehdizadeh, Fariba Eslamian, Alireza Pishgahi, Mehdi Yousefi
Commercial kit (Noavaran Salamat Arzhang, Iran) was used to prepare PL. 20 ml of whole blood was withdrawn from each patient in acid citrate dextrose formula A (ACD-A) anticoagulant to obtain PRP. PL preparation was done based on standard protocol (Schallmoser and Strunk 2009; Yin et al. 2017). Briefly, blood samples were centrifuged twice (the first time at 160 g for 10 min in 20 °C to separate erythrocytes, and the second time at 250 g for 15 min in 20 °C to obtain a platelet pellets. An aliquot of the product was analyzed for a quality test (leukocyte count, platelet count, and bacteriological test). The final product of PRP was almost pure PRP with platelet concentration about 4.2–4.6 times greater than that in the whole blood. Platelet Lysate was prepared from PRP by carrying out two sequential freeze/thaw cycles on PRP aliquots (freezing at −80 °C, each time for 60 min, rapidly thawing at 37 °C for 10 min) in order to induce platelet lysis and the release of their protein content. The samples were homogenized between cycles (15-s vortex). Then, the thawed and activated plasma was centrifuged at 400 g for 20 min at room temperature to remove membrane debris. Autologous PL containing the cocktail of factors liberated from the platelets was obtained after filtration through 0.45 and 0.22-μm membrane filters. Filtered PL was divided in aliquots and stored at −80 °C until further use.
In vitro evaluation of platelet extracellular vesicles (PEVs) for corneal endothelial regeneration
Published in Platelets, 2022
Rifa Widyaningrum, Yu-Wen Wu, Liling Delila, Deng-Yao Lee, Tsung-Jen Wang, Thierry Burnouf
One relevant limitation of our study is that we did not compare the functional activity of these PEVs to that of a platelet lysate. This is due to several reasons. First, we wanted to prove first the functional activity of the PEV in the particular CEC model used. Second, the PEVs used in this study, by contrast to our previous recent work [79], were isolated from the plasma supernatant of a platelet concentrate, not from a platelet lysate, therefore constituting a stand-alone product of its own. Nevertheless, experiments comparing a full platelet lysate (which contains both free proteins and PEV), isolated PEVs, and PEV-depleted platelet lysate would be valuable to discriminate the respective role of free trophic factors and PEVs in the repair of the damaged corneal endothelium. In a very recent study using a dedicated heat-treated platelet lysate for brain administration, we have found that the PEV depletion of this material by nanofiltration on 19-nm filter, did not significantly affect the neuroprotective and anti-inflammatory activities in cellular and animal models [81]. This suggested that for this specific platelet lysate and that particular application, the PEV did not exert a major contribution to functionality.
Antiplatelet activity of deferiprone through cyclooxygenase-1 inhibition
Published in Platelets, 2020
Ngan Thi Tran, Benjaporn Akkawat, Noppawan Phumala Morales, Ponlapat Rojnuckarin, Rataya Luechapudiporn
Washed platelets (5 × 109 platelets/ml) containing 1% protease inhibitor cocktail were sonicated and centrifuged at 10000g, 4°C, for 15 minutes to obtain platelet lysates. Platelet lysate (1 mg/ml protein) was pre-treated with or without various concentrations of deferiprone or aspirin for 5 minutes at 25°C. The COX-1 activity of the samples was determined by the COX-1 fluorescent activity assay kit. Briefly, AA (0.1 mmol/l) was added to initiate the reaction. The COX-1 enzyme in platelet lysates converted AA to prostaglandin G2 (PGG2), and then the reaction of PGG2 and ADHP (10-acetyl-3,7-dihyroxyhenoxazine) produced fluorescent resorufin. Resorufin was quantified using an excitation wavelength of 530–540 nm and an emission wavelength of 585–595 nm.