Subtalar osteoarthritis (STOA) is often secondary to chronic ankle sprains, which seriously affects the quality of life of patients. Due to its etiology and pathogenesis was not studied equivocally yet, there is currently a lack of effective conservative treatments. Although they have been used for tissue repair, platelet-rich plasma-derived exosomes (PRP-Exo) have the disadvantage of low retention and short-lived therapeutic effects. This study aimed to determine whether incorporation of PRP-Exo in thermosensitive hydrogel (Gel) increased their retention in the joint and thereby playing a therapeutic role on STOA due to chronic mechanical instability established by transecting lateral ligaments (anterior talofibular ligament (ATFL)/calcaneal fibular ligament (CFL)).
PRP-Exo incorporated Gel (Exo-Gel) system, composed of <em>Poloxamer</em>-407 and <em>188</em> mixture-based thermoresponsive hydrogel matrix in an optimal ratio, was determined by its release ability of Exo and rheology of Gel response to a different temperature. The biological activity of Exo-Gel was evaluated in vitro, and the therapeutic effect of Exo-Gel on STOA was evaluated in vivo.
Exo released from Exo-Gel continuously for 28 days could promote the proliferation and migration of mouse bone mesenchymal stem cells (mBMSCs) and chondrocytes, at the same time enhance the chondrogenic differentiation of mBMSCs, and inhibit inflammation-induced chondrocyte degeneration. In vivo experiments confirmed that Exo-Gel increased the local retention of Exo, inhibited the apoptosis and hypertrophy of chondrocytes, enhanced their proliferation, and potentially played the role in stem cell recruitment to delay the development of STOA. Thus, Delivery of PRP-Exo incorporated in thermosensitive Gel provides a novel approach of cell-free therapy and has therapeutic effect on STOA.
Aquaporin 4 in Traumatic Brain Injury: From Molecular Pathways to Therapeutic Target
Traumatic brain injury (TBI) is known as an acute degenerative pathology of the central nervous system, and has been shown to increase brain aquaporin 4 (AQP4) expression. Various molecular mechanisms affect AQP4 expression, including neuronal high mobility group box 1, forkhead box O3a, vascular endothelial growth factor, hypoxia-inducible factor-1 α (HIF-1 α) sirtuin 2, NF-κB, Malat1, nerve growth factor and Angiotensin II receptor type 1. In addition, inhibition of AQP4 with FK-506, MK-801 (indirectly by targeting N-methyl-D-aspartate receptor), inactivation of adenosine A2A receptor, levetiracetam, adjudin, progesterone, estrogen, V1aR inhibitor, hypertonic saline, erythropoietin, <em>poloxamer</em> <em>188</em>, brilliant blue G, HIF-1alpha inhibitor, normobaric oxygen therapy, astaxanthin, epigallocatechin-3-gallate, sesamin, thaliporphine, magnesium, prebiotic fiber, resveratrol and omega-3, as well as AQP4 gene silencing lead to reduced edema upon TBI. This review summarizes current knowledge and evidence on the relationship between AQP4 and TBI, and the potential mechanisms involved.
Solvent-Free Fabrication of Biphasic Lipid-Based Microparticles with Tunable Structure
Lipid-based biphasic microparticles are generally produced by long and complex techniques based on double emulsions. In this study, spray congealing was used as a solvent-free fabrication method with improved processability to transform water-in-oil non-aqueous emulsions into spherical solid lipid-based particles with a biphasic structure (b-MPs).
Emulsions were prepared by melt emulsification using different compositions of lipids (Dynasan<sup>®</sup>118 and Compritol<sup>®</sup>888 ATO), surfactants (Cetylstearyl alcohol and Span<sup>®</sup>60) and hydrophilic carriers (PEGs, Gelucire<sup>®</sup>48/16 and <em>Poloxamer</em> <em>188</em>).
First, pseudo-ternary phase diagrams were constructed to identify the area corresponding to each emulsion type (coarse emulsion or microemulsion). The hydrophobicity of the lipid mostly affected the interfacial tension, and thus the microstructure of the emulsion. Emulsions were then processed by spray congealing and the obtained b-MPs were characterized in terms of thermal and chemical properties (by DSC and FT-IR), external and internal morphology (by SEM, CLSM and Raman mapping).
Solid free-flowing spherical particles (main size range 200-355 µm) with different architectures were successfully produced: microemulsions led to the formation of particles with a homogeneous internal structure, while coarse emulsions generated “multicores-shell” particles consisting of variable size hydrophilic cores evenly distributed within the crystalline lipid phase. Depending on their composition and structure, b-MPs could achieve various release profiles, representing a more versatile system than microparticles based on a single lipid phase. The formulation and technological strategy proposed, provides a feasible and cost-effective way of fabricating b-MPs with tunable internal structure and release behavior.
Genome DNA Leakage of Adeno-Associated Virus Under Freeze-Thaw Stress
Adeno-associated virus (AAV) has become an emerging tool for human gene therapies. Currently, AAV gene therapies are subjected to multiple freeze-thaw cycles during manufacturing, storage, transportation, and administration. While studies have shown that multiple freeze-thaw cycles led to a decrease in transduction efficiency, the AAV degradation mechanism during freeze-thaw is not well understood.
Here, we have characterized the impact of freeze-thaw on AAV8 by employing a variety of assays, which revealed significant increases in the amount of free single-stranded DNA (ssDNA) in AAV8 formulations after multiple freeze-thaw cycles. Subsequent analysis using Next Generation Sequencing (NGS) revealed that the ssDNA primarily consisted of genome DNA, indicating that the increased ssDNA leaked out from AAV8.
Experiments performed using different serotypes of AAV confirmed the pervasiveness of such behavior amongst AAVs. In addition, formulation screening studies were performed to understand the impact on genome DNA leakage from AAV. The formulation screening results showed that the addition of 10% sucrose and 0.1% <em>poloxamer</em> <em>188</em> to Dulbecco’s phosphate-buffered saline (DPBS) reduced the leakage of ssDNA in AAV samples after freeze-thaw cycles compared to the base formulation of DPBS alone. These findings shed new light on the degradation mechanism of AAVs and stabilization of the AAV-based gene therapies.
Sustained Delivery of Lactoferrin Using Poloxamer Gels for Local Bone Regeneration in a Rat Calvarial Defect Model
Lactoferrin (LF) is a multifunctional milk glycoprotein that promotes bone regeneration. Local delivery of LF at the bone defect site is a promising approach for enhancement of bone regeneration, but efficient systems for sustained local delivery are still largely missing. The aim of this study was to investigate the potential of the poloxamers for sustained delivery of LF to enhance local bone regeneration. The developed LF/poloxamer formulations were liquid at room temperature (20 °C) transforming to a sustained releasing gel depot at body temperature (37 °C). In vitro release studies demonstrated an initial burst release (~50%), followed by slower release of LF for up to 72 h.
Poloxamer 188from MyBiosource |
MBS5785744-500mg |
500(mg: 150.00 EUR |
Poloxamer 188from MyBiosource |
MBS5785744-5x500mg |
5x500(mg: 525.00 EUR |
Poloxamer 188from TargetMol Chemicals |
T40802-10mg |
10mg: Ask for price |
Poloxamer 188from TargetMol Chemicals |
T40802-1g |
1g: Ask for price |
Poloxamer 188from TargetMol Chemicals |
T40802-1mg |
1mg: Ask for price |
Poloxamer 188from TargetMol Chemicals |
T40802-50mg |
50mg: Ask for price |
Poloxamer 188from TargetMol Chemicals |
T40802-5mg |
5mg: Ask for price |
100mL Poloxamer 188 - PK6from Scientific Laboratory Supplies |
13-901-CI |
PK6: 137.70 EUR |
100 G POLOXAMER 188, POWDERfrom CORNING |
61-161-RM |
100 g/pk: 80.40 EUR |
Poloxamer 407from MyBiosource |
MBS5756098-5mg |
5mg: 145.00 EUR |
Poloxamer 407from MyBiosource |
MBS5756098-5x5mg |
5x5mg: 500.00 EUR |
Poloxamer 407from TargetMol Chemicals |
T19524-10mg |
10mg: Ask for price |
Poloxamer 407from TargetMol Chemicals |
T19524-1g |
1g: Ask for price |
Poloxamer 407from TargetMol Chemicals |
T19524-1mg |
1mg: Ask for price |
Poloxamer 407from TargetMol Chemicals |
T19524-50mg |
50mg: Ask for price |
Poloxamer 407from TargetMol Chemicals |
T19524-5mg |
5mg: Ask for price |
Poloxamer Solidfrom Toronto Research Chemicals |
P688040 |
100g: 64.00 EUR |
Poloxinfrom MedKoo Biosciences |
406449 |
10.0mg: 250.00 EUR |
Poloxinfrom ApexBio |
A3732-10 |
10 mg: 44.00 EUR |
Poloxamer, with and without LF, increased osteoblast viability at 72 h (p < 0.05) compared to control, and the immune response from THP-1 cells was mild when compared to the suture material. In rat calvarial defects, the LF/poloxamer group had lower bone volume than the controls (p = 0.0435). No difference was observed in tissue mineral density and lower bone defect coverage scores (p = 0.0267) at 12 weeks after surgery. In conclusion, LF/poloxamer formulations support cell viability and do not induce an unfavourable immune response; however, LF delivery via the current formulation of LF200/poloxamer gel did not demonstrate enhanced bone regeneration and was not compatible with the rat calvarial defect model.