Performance of PRP associated with porous chitosan as a composite scaffold for regenerative medicine

Synthesis and physicochemical characterization of rhamnolipid fabricated fucoxanthin loaded bovine serum albumin nanoparticles supported by simulation studies

BACKGROUND

Fucoxanthin is a hydrophobic carotenoid with many beneficial biological activities. However, due to low aqueous solubility their clinical efficacy is limited thus leading to poor oral bioavailability. To address this issue, we encapsulated fucoxanthin in rhamnolipid fabricated bovine serum albumin (BSA) loaded nanoparticles (LNPs) for improving solubility dependent bioavailability of fucoxanthin.

RESULTS

These synthesized LNPs were characterized by dynamic light scattering (DLS), ultraviolet (UV)-visible spectrophotometry, high-performance liquid chromatography (HPLC), Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC). Our results showed that LNPs were spherical in shape with particle size around 180 nm along with positive zeta potential. The encapsulation efficiency and loading efficiency calculated for LNPs were 69.66 ± 1.5% and 14 ± 0.2%, respectively. The antioxidant assay of LNPs indicate high radical scavenging activity compared to pure fucoxanthin. Besides this, our release studies indicates that drug release occur from the matrix of nanocarrier system through diffusion based on concentration. Thus, these findings indicate successful encapsulation of fucoxanthin, with improved solubility thereby leading to increased bioavailability. This nano formulation is derived from components which are FDA approved that could be exploited for encapsulating other vital nutraceutical molecules.

CONCLUSION

Overall, our results showed successful synthesis of biodegradable nanocarrier for delivering fucoxanthin supported by molecular docking, molecular dynamics simulation and thermodynamics of free binding energy studies. © 2022 Society of Chemical Industry.

Physico-chemical characterization of carvacrol loaded zein nanoparticles for enhanced anticancer activity and investigation of molecular interactions between them by molecular docking

Carvacrol (CV), a monoterpene possesses wide range of biological activities but has limited application due to low aqueous solubility and poor bioavailability. To address this issue and enhance bioavailability and efficacy of carvacrol, lecithin stabilized zein nanoparticles were investigated. Precipitation method was used for synthesis of nanoparticles and characterized using various techniques. CV entrapped under optimized parameters has size around 250 nm with -15 mV zeta potential. SEM studies showed nanoparticles with spherical morphology and size in accordance with DLS studies. FTIR, NMR and DSC were used to determine the molecular interaction between CV and lecithin stabilized zein nanoparticles. Molecular docking studies were performed to understand the interaction between protein and drug at molecular level. Our results demonstrated the presence of two active sites within zein, showing strong binding interactions with carvacrol. The encapsulation efficiency of 78% with loading efficiency of 13% was obtained as per HPLC and UV-Vis studies. Cytotoxicity assay indicated that the CV loaded nanoparticles induce cytotoxicity against colon cancer (SW480) cells further confirmed by acridine orange and ethidium bromide dual staining assay. Fluorescent tagged nanoparticles revealed significant cellular uptake of drug. Our results suggest that CV can be conveniently delivered via oral route after incorporating into lecithin stabilized zein nanoparticles and may prove effective for colon cancer treatment.

Effectiveness of mesenchymal stem cell-seeded onto the 3D polylactic acid/polycaprolactone/hydroxyapatite scaffold on the radius bone defect in rat

PURPOSE

The importance of regeneration in large bone defects forces the orthopedic surgeons to search for a proper methodology. The present experiment evaluated the capability of polylactic acid/polycaprolactone/hydroxyapatite (PLA/PCL/HA) scaffold loaded with and without mesenchymal stem cells (MSCs) on bone regeneration.

METHODS

Fourier transform infrared spectrometry, X-ray diffraction, scanning electron microscopy, and rheology methodologies were used to characterize the scaffold. Forty Wistar rats were randomly divided into the four groups including the untreated defects as the control group and three other groups in which the bone defects were treated with autologous bones (autograft group), the PLA/PCL/HA scaffolds (PLA/PCL/HA group), and the MSCs-seeded scaffolds (MSCs-seeded PLA/PCL/HA group).

RESULTS

Based on the qRT-PCR results, significantly higher expression levels of osteocalcin, osteopontin, and CD31 were seen in the cell-seeded scaffold group compared to the control group (P < 0.05). The CT scanning and radiographic images depicted significantly more newly formed bonny tissue in the MSCs-loaded scaffold and autograft groups than the untreated group (P < 0.001). The immunohistochemistry, biomechanical, histopathologic, and histomorphometric evaluations demonstrated significantly improved regeneration in the autograft and MSCs-loaded scaffold groups compared to the non-treated group (P < 0.05). There were significant differences between the scaffold and untreated groups in all in vivo evaluations (P < 0.05).

CONCLUSION

The MSCs enhanced bone healing potential of the PLA/PCL/HA scaffold and the MSCs-seeded scaffold was comparable to the autograft as the golden treatment regimen (P > 0.05).

Multiple platelet-rich plasma preparations can solubilize freeze-dried chitosan formulations to form injectable implants for orthopedic indications

BACKGROUND

Platelet-rich plasma (PRP) has been used to solubilize freeze-dried chitosan (CS) formulations to form injectable implants for tissue repair.

OBJECTIVE

To determine whether the in vitro performance of the formulations depends on the type of PRP preparation used to solubilize CS.

METHODS

Formulations containing 1% (w/v) CS with varying degrees of deacetylation (DDA 80.5-84.8%) and number average molar mass (Mn 32-55 kDa), 1% (w/v) trehalose and 42.2 mM calcium chloride were freeze-dried. Seven different PRP preparations were used to solubilize the formulations. Controls were recalcified PRP.

RESULTS

CS solubilization was achieved with all PRP preparations. CS-PRP formulations were less runny than their corresponding PRP controls. All CS-PRP formulations had a clotting time below 9 minutes, assessed by thromboelastography, while the leukocyte-rich PRP controls took longer to coagulate (>32 min), and the leukocyte-reduced PRP controls did not coagulate in this dynamic assay. In glass culture tubes, all PRP controls clotted, expressed serum and retracted (43-82% clot mass lost) significantly more than CS-PRP clots (no mass lost). CS dispersion was homogenous within CS-PRP clots.

CONCLUSIONS

In vitro performance of the CS-PRP formulations was comparable for all types of PRPs assessed.

Centrifugation Conditions in the L-PRP Preparation Affect Soluble Factors Release and Mesenchymal Stem Cell Proliferation in Fibrin Nanofibers

Leukocyte and platelet-rich plasma (L-PRP) is an autologous product that when activated forms fibrin nanofibers, which are useful in regenerative medicine. As an important part of the preparation of L-PRP, the centrifugation parameters may affect the release of soluble factors that modulate the behavior of the cells in the nanofibers. In this study, we evaluated the influences of four different centrifugation conditions on the concentration of platelets and leukocytes in L-PRP and on the anabolic/catabolic balance of the nanofiber microenvironment. Human adipose-derived mesenchymal stem cells (h-AdMSCs) were seeded in the nanofibers, and their viability and growth were evaluated. L-PRPs prepared at 100× g and 100 + 400× g released higher levels of transforming growth factor (TGF)-β1 and platelet-derived growth factor (PDGF)-BB due to the increased platelet concentration, while inflammatory cytokines interleukin (IL)-8 and tumor necrosis factor (TNF)-α were more significantly released from L-PRPs prepared via two centrifugation steps (100 + 400× g and 800 + 400× g) due to the increased concentration of leukocytes. Our results showed that with the exception of nanofibers formed from L-PRP prepared at 800 + 400× g, all other microenvironments were favorable for h-AdMSC proliferation. Here, we present a reproducible protocol for the standardization of L-PRP and fibrin nanofibers useful in clinical practices with known platelet/leukocyte ratios and in vitro evaluations that may predict in vivo results.

The Use of Platelet-Rich Plasma to Promote Cell Recruitment into Low-Molecular-Weight Fucoidan-Functionalized Poly(Ester-Urea-Urethane) Scaffolds for Soft-Tissue Engineering

Due to their elastomeric behavior, polyurethane-based scaffolds can find various applications in soft-tissue engineering. However, their relatively inert surface has to be modified in order to improve cell colonization and control cell fate. The present study focuses on porous biodegradable scaffolds based on poly(ester-urea-urethane), functionalized concomitantly to the scaffold elaboration with low-molecular-weight (LMW) fucoidan; and their bio-activation with platelet rich plasma (PRP) formulations with the aim to promote cell response. The LMW fucoidan-functionalization was obtained in a very homogeneous way, and was stable after the scaffold sterilization and incubation in phosphate-buffered saline. Biomolecules from PRP readily penetrated into the functionalized scaffold, leading to a biological frame on the pore walls. Preliminary in vitro assays were assessed to demonstrate the improvement of scaffold behavior towards cell response. The scaffold bio-activation drastically improved cell migration. Moreover, cells interacted with all pore sides into the bio-activated scaffold forming cell bridges across pores. Our work brought out an easy and versatile way of developing functionalized and bio-activated elastomeric poly(ester-urea-urethane) scaffolds with a better cell response.

Biomaterials as cell carriers for augmentation of adipose tissue-derived stromal cell transplantation

Adipose tissue-derived stromal cells (ADSCs) contain lineage-committed progenitor cells that have the ability to differentiate into various cell types that may be useful for autologous cell transplantation to correct defects of skin, adipose, cartilage, bone, tendon, and blood vessels. The multipotent characteristics of ADSCs, as well as their abundance in the human body, make them an attractive potential resource for wound repair and applications to tissue engineering. ADSC transplantation has been used in combination with biomaterials, including cell sheets, hydrogel, and three-dimensional (3D) scaffolds based on chitosan, fibrin, atelocollagen, and decellularized porcine dermis, etc. Furthermore, low molecular weight heparin/protamine nanoparticles (LH/P NPs) have been used as an inducer of ADSC aggregation. The tissue engineering potential of these biomaterials as cell carriers is increased by the synergistic relationship between ADSCs and the biomaterials, resulting in the release of angiogenic cytokines and growth factors. In this review article, we describe the advantages of ADSC transplantation for tissue engineering, focusing on biomaterials as cell carriers which we have studied.

Effectiveness of tissue engineered based platelet gel embedded chitosan scaffold on experimentally induced critical sized segmental bone defect model in rat

BACKGROUND

Healing and regeneration of large bone defects are a challenging problem for reconstructive orthopedic surgeons.

PURPOSE

This study investigated the effectiveness of chitosan scaffold (CS), platelet gel (PG) and their combination (CS-PG) on healing process of an experimentally induced critical sized segmental bone defect model in rat.

METHODS

Fifty bilateral defects were created in the mid diaphysis of the radial bones of 25 Sprague-Dawley rats. The animals were randomly divided into five equal groups. The bone defects were either left untreated or treated with corticomedullary autograft, CS, PG or CS-PG. Plain radiographs were provided from the radial bones on weeks 2, 5, and 8 after injury. In addition, clinical examinations were done for the healing radial bones. The animals were euthanized after 8 weeks of injury, and their harvested samples were evaluated by gross morphology, histopathology, scanning electron microscopy, CT-scan, and biomechanical testing.

RESULTS

Compared with the defect group, the PG and autograft treated bone defects had significantly superior radiological scored values, bone volume and biomechanical performance which had positive correlation with their superior gross pathological, histopathological and ultra-structural features. Compared with the untreated defects, the PG and CS-PG treated defects showed significantly superior structural and functional properties so that PG had the highest value. In addition, CS had low value in bone regeneration. Although combination of CS and PG improved the healing efficacy of the CS, this strategy reduced the ability of PG to increase osteoconduction and osteoinduction during bone regeneration.

CONCLUSION

Application of PG alone enhanced bone healing and can be regarded as a promising option for bone tissue engineering in clinical settings. Chitosan was not effective in bone reconstruction surgery and further investigations should be conducted to find a suitable carrier for PG.

Human platelet-rich plasma improves the nesting and differentiation of human chondrocytes cultured in stabilized porous chitosan scaffolds

The clinical management of large-size cartilage lesions is difficult due to the limited regenerative ability of the cartilage. Different biomaterials have been used to develop tissue engineering substitutes for cartilage repair, including chitosan alone or in combination with growth factors to improve its chondrogenic properties. The main objective of this investigation was to evaluate the benefits of combining activated platelet-rich plasma with a stabilized porous chitosan scaffold for cartilage regeneration. To achieve this purpose, stabilized porous chitosan scaffolds were prepared using freeze gelation and combined with activated platelet-rich plasma. Human primary articular chondrocytes were isolated and cultured in stabilized porous chitosan scaffolds with and without combination to activated platelet-rich plasma. Scanning electron microscopy was used for the morphological characterization of the resulting scaffolds. Cell counts were performed in hematoxylin and eosin–stained sections, and type I and II collagen expression was evaluated using immunohistochemistry. Significant increase in cell number in activated platelet-rich plasma/stabilized porous chitosan was found compared with stabilized porous chitosan scaffolds. Chondrocytes grown on stabilized porous chitosan expressed high levels of type I collagen but type II was not detectable, whereas cells grown on activated platelet rich plasma/stabilized porous chitosan scaffolds expressed high levels of type II collagen and type I was almost undetectable. In summary, activated platelet-rich plasma increases nesting and induces the differentiation of chondrocytes cultured on stabilized porous chitosan scaffolds.

In vitro performance of injectable chitosan-tripolyphosphate scaffolds combined with platelet-rich plasma

This study aimed to evaluate the in vitro biological effectiveness of chitosan microparticles crosslinked with sodium tripolyphosphate (TPP) in combination with activated pure platelet-rich plasma (aP-PRP) as an injectable composite scaffold for growth factors release, cell proliferation and osteogenic differentiation. Two main novelties were addressed in the field of scaffolds in regenerative medicine: the first is the approach including simultaneously the three vertices of the proliferation triangle formed by the capabilities genic progenitor cells, conductive scaffolds and inductive growth factors, which are provided by platelet rich plasma (PRP); secondly, the approach of an injectable composite scaffolds formed by the fibrin network from aP-PRP and the chitosan microparticles crosslinked with TPP. The microparticles were prepared by vortexing the chitosan and TPP solutions. The ionic crosslinking of chitosan with TPP was made at mass ratios of 2:1, 5:1, and 10:1 at pH 4.0. P-PRP was obtained via the controlled centrifugation of whole blood. The composite scaffolds were prepared by adding the microparticles to immediately activated P-PRP. The results showed that the microparticles had adequate physicochemical and mechanical properties for injection. Furthermore, the microparticles controlled the release of growth factors from P-PRP. The proliferation of human adipose-derived mesenchymal stem cells was lower than in aP-PRP alone but significant at a 2:1 chitosan-TPP mass ratio. Osteogenic differentiation was stimulated at all studied mass ratios, as indicated by the alkaline phosphatase activity. These results offer perspectives for optimizing the composite scaffold, and to prove its potential as an injectable scaffold in regenerative medicine.