Biocompatibility and hemocompatibility of polyvinyl alcohol hydrogel used for vascular grafting-<i>In vitro</i>and<i>in vivo</i>studies

The preparation and characterization of a porous hybrid cryogel based on the two organic polymers, poly(vinyl alcohol) (PVA) and karaya gum (KG), into which polyphosphate (polyP) nanoparticles have been incorporated, are described. The PVA/KG cryogel is prepared by intermolecular cross‐linking of PVA via freeze‐thawing and Ca2+‐mediated ionic gelation of KG to form stable salt bridges. The incorporation of polyP as amorphous nanoparticles with Ca2+ ions (Ca‐polyP‐NP) is achieved using an in situ approach. The polyP constituent does not significantly affect the viscoelastic properties of the PVA/KG cryogel that are comparable to natural soft tissue. The exposure of the Ca‐polyP‐NP within the cryogel to medium/serum allows the formation of a biologically active polyP coacervate/protein matrix that stimulates the growth of human mesenchymal stem cells in vitro and provides the cells a suitable matrix for infiltration superior to the polyP‐free cryogel. In vivo biocompatibility studies in rats reveal that already two to four weeks after implantation into muscle, the implant regions containing the polyP‐KG/PVA material become replaced by initial granulation tissue, whereas the controls are free of any cells. It is proposed that the polyP‐KG/PVA cryogel has the potential to become a promising implant material for soft tissue engineering/repair.

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“…[38,61] PVA is more stiff and tough in comparison to KG. [38,61] PVA is more stiff and tough in comparison to KG.…”

Section: Discussionmentioning

confidence: 98%

In Situ Polyphosphate Nanoparticle Formation in Hybrid Poly(vinyl alcohol)/Karaya Gum Hydrogels: A Porous Scaffold Inducing Infiltration of Mesenchymal Stem Cells

et al. 2018

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“…With such robust results, the use of WJ-MSCs became a large step in overcoming limiting factors in repairing congenital malformations. These efficacy readouts have also been confirmed in large animal studies, where engineered heart tissues were successfully transplanted into sheep, even showing good functional performance after 20 weeks [28]. However, uncertainty still remains over whether these engineered tissues can survive successfully in the long-term [29].…”

Section: Cell Therapy For Cardiovascular and Connective Tissue Repairmentioning

confidence: 90%

“…The cells have been used in large animal studies with the sheep hearts functioning over 20 weeks into experimentation [28]. …”

Section: Figurementioning

confidence: 99%

Discarded Wharton jelly of the human umbilical cord: a viable source for mesenchymal stromal cells

Watson¹,

Divers²,

Kedar

et al. 2015

Cytotherapy

106

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Mesenchymal stem cells (MSCs) are multipotent cells that have the capability of differentiating into adipogenic, osteogenic, chondrogenic, and neural cells. With these multiple capabilities, MSCs have been highly regarded as effective transplantable cell source for regenerative medicine. A large bank of these cells can be found in several regions of the human umbilical cord (hUC) including the umbilical cord lining, the subendothelial layer, the perivascular zone, and most importantly in Wharton’s jelly (WJ). These cells, all umbilical cord-derived MSCs, are very durable, have large loading capacities, and are considered ethical to harvest because the umbilical cord is often considered a waste. These logistical advantages make WJ as appealing source of stem cells for transplant therapy. In particular, WJ is a predominantly good source of cells because MSCs in WJ (WJ-MSC) are maintained in a very early embryological phase and therefore have retained some of the primitive stemness properties. WJ-MSCs can easily differentiate into a plethora of cell types leading to a variety of applications. In addition, WJ-MSCs are slightly easier to harvest compared to other MSCs (such as bone marrow-derived MSCs). The fascinating stemness properties and therapeutic potential of WJ-MSCs provide great promise in many aspects of regenerative medicine and should be considered for further investigations as safe and effective donor cells for transplantation therapy in many debilitating disorders, which are discussed here. We previously reviewed WJ-MSCs therapeutic potential [1] and now provide an update on their recent preclinical and clinical applications.

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“…The biocompatibility of PVA is recognized as good. 2 Intolerance reactions to PVA are not known. A recent literature review did not indicate unexpected biodegradability of PVA membranes in ASD closure devices.…”

Section: Discussionmentioning

confidence: 99%

Early Malfunction of Polyvinyl Alcohol Membrane–Covered Atrial Septal Defect Closure Devices

Aubry

Brochet²,

Fretay³

et al. 2014

Circ: Cardiovascular Interventions

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A 77-year-old man was referred for treatment of a secundum type atrial septal defect (ASD). Transthoracic echocardiography and transesophageal echocardiography showed a 20-mm atrial ASD (Figure [A]) with important enlargement of the right ventricle. A 24-mm ASD Ultrasept II (Cardia Inc, Eagan, MN) closure device was successfully implanted (Figure [B]) after the first attempt with no residual shunt. The Ultrasept II device was loaded and deployed in a similar manner to Amplatzer devices. The nickel-titanium frame of the Ultrasept II device has 2 discs covered with a polyvinyl alcohol (PVA) membrane ( . In follow-up at 8 months the patient was well. Thereafter, a routine transthoracic echocardiography was performed at 3 months of all patients (n=9) implanted with the ASD Ultrasept II device in our institution. One other similar case was diagnosed: a 41-year-old woman referred for treatment of an ASD associated with moderate enlargement of the right ventricle. Transesophageal echocardiography showed a 19-mm defect associated with thin margins. A 32-mm ASD Ultrasept II closure device was implanted successfully with no residual shunt. One-week and one-month echocardiographic followup were unremarkable. A routine transthoracic echocardiography performed at 3 months revealed a recurrent significant left-to-right shunt. Transesophageal echocardiography, intraoperative, and explanted images were similar to those described as in the first case. Surgical device removal and Gore-Tex patch repair were performed with an uneventful follow-up at 6 months. DiscussionTwo early malfunctions of the PVA membrane were observed in a series of 9 consecutive patients treated with ASD Ultrasept II closure device in our institution. Implantation of a second device within the defective device was discussed, but surgery repair was preferred because of the unclear mechanism of the malfunction. Two similar cases were previously reported 1 with the ASD Atriasept II (Cardia Inc, Eagan, MN) closure device, a previous generation of the device used in the current cases, which also uses a PVA-based material. The mechanism of PVA membrane disappearance was not reported. PVA is a water-soluble polymer, which becomes insoluble for medical purposes with formaldehyde or glutaraldehyde cross links. The biocompatibility of PVA is recognized as good.2 Intolerance reactions to PVA are not known. A recent literature review did not indicate unexpected biodegradability of PVA membranes in ASD closure devices.3 An usual procedure followed for our 2 cases included soaking of the device in sterile saline before loading in the delivery sheath. A severe adverse event notification form was sent to the manufacturer. The 2 devices were not from the same manufacturing lot. The explanted devices were macroscopically and microscopically examined. The metallic frame and all sutures used to attach the PVA membrane to the frame were intact. Examination of the residual PVA membrane was unremarkable. All processes used to create the PVA membranes were reviewed. Several chemic...

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Biocompatibility and hemocompatibility of polyvinyl alcohol hydrogel used for vascular grafting-In vitroandin vivostudies

Cited by 89 publications

References 58 publications

In Situ Polyphosphate Nanoparticle Formation in Hybrid Poly(vinyl alcohol)/Karaya Gum Hydrogels: A Porous Scaffold Inducing Infiltration of Mesenchymal Stem Cells

In Situ Polyphosphate Nanoparticle Formation in Hybrid Poly(vinyl alcohol)/Karaya Gum Hydrogels: A Porous Scaffold Inducing Infiltration of Mesenchymal Stem Cells

Discarded Wharton jelly of the human umbilical cord: a viable source for mesenchymal stromal cells

Early Malfunction of Polyvinyl Alcohol Membrane–Covered Atrial Septal Defect Closure Devices

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