Human Fibroblast Growth Research Articles

Implanted synthetic cells trigger tissue angiogenesis through de novo production of recombinant growth factors.

Progress in bottom-up synthetic biology has stimulated the development of synthetic cells (SCs), autonomous protein-manufacturing particles, as dynamic biomimetics for replacing diseased natural cells and addressing medical needs. Here, we report that SCs genetically encoded to produce proangiogenic factors triggered the physiological process of neovascularization in mice. The SCs were constructed of giant lipid vesicles and were optimized to facilitate enhanced protein production. When introduced with the appropriate genetic code, the SCs synthesized a recombinant human basic fibroblast growth factor (bFGF), reaching expression levels of up to 9⋅106 protein copies per SC. In culture, the SCs induced endothelial cell proliferation, migration, tube formation, and angiogenesis-related intracellular signaling, confirming their proangiogenic activity. Integrating the SCs with bioengineered constructs bearing endothelial cells promoted the remodeling of mature vascular networks, supported by a collagen-IV basement membrane-like matrix. In vivo, prolonged local administration of the SCs in mice triggered the infiltration of blood vessels into implanted Matrigel plugs without recorded systemic immunogenicity. These findings emphasize the potential of SCs as therapeutic platforms for activating physiological processes by autonomously producing biological drugs inside the body.

Mechanical Properties and In Vitro Biocompatibility of Hybrid Polymer-HA/BAG Ceramic Dental Materials

The aim of this study is to prepare hybrid polymer–ceramic dental materials for chairside computer-aided design/computer-aided manufacturing (CAD/CAM) applications. The hybrid polymer–ceramic materials were fabricated via infiltrating polymerizable monomer mixtures into sintered hydroxyapatite/bioactive glass (HA/BAG) ceramic blocks and thermo-curing. The microstructure was observed by scanning electron microscopy and an energy-dispersive spectrometer. The phase structure was analyzed by X-ray diffraction. The composition ratio was analyzed by a thermogravimetric analyzer. The hardness was measured by a Vickers hardness tester. The flexural strength, flexural modulus, and compressive strength were measured and calculated by a universal testing machine. The growth of human gingival fibroblasts was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) colorimetric assay and immunofluorescence staining. The results showed that the sintering temperature and BAG content affected the mechanical properties of the hybrid polymer–ceramic materials. The X-ray diffraction analysis showed that high-temperature sintering promoted the partial conversion of HA to β-tricalcium phosphate. The values of the hardness, flexural strength, flexural modulus, and compressive strength of all the hybrid polymer–ceramic materials were 0.89–3.51 GPa, 57.61–118.05 MPa, 20.26–39.77 GPa, and 60.36–390.46 MPa, respectively. The mechanical properties of the hybrid polymer–ceramic materials were similar to natural teeth. As a trade-off between flexural strength and hardness, hybrid polymer–ceramic material with 20 wt.% BAG sintered at 1000 °C was the best material. In vitro experiments confirmed the biocompatibility of the hybrid polymer–ceramic material. Therefore, the hybrid polymer–ceramic material is expected to become a new type of dental restoration material.

Antimicrobial Efficacy of Continuous Low-Irradiance Phototherapy Against Multidrug-Resistant Organisms.

Objective: The objective of this study is to report on the bactericidal effects of blue light administered at low irradiance for extended periods of time. Background: Multidrug-resistant organisms (MDROs) utilize biofilms that can limit the efficacy of antibiotics, causing infection and impaired wound healing. Unlike high-energy systems, continuous low-irradiance phototherapy (CLIP) avoids thermal injury of healthy tissue and can be delivered for extended periods. Methods: Four MDRO species, two of which contained different antibiotic resistance genes, were exposed to 405 nm irradiation in vitro. The microbes were incrementally exposed to increasing dose-rates (irradiance; mW/cm2) over a 24-h time period. Cell viability and biomass reduction assays were conducted to quantify the antibacterial/antibiofilm effects. Primary human dermal fibroblasts were also exposed to CLIP to assess whether these dose-rates would impair cell viability or proliferation. Results: CLIP exposure utilizing irradiances as low as 2.78 mW/cm2 delivered over 24 h resulted in a >3.0-log (>99.9%) and >2.0-log (>99.0%) microbial load reduction when organisms were grown in planktonic and biofilm-encapsulated conditions, respectively. Crystal violet biofilm assays revealed destruction of extracellular biofilm architecture following CLIP exposure. Human fibroblast viability and proliferation were unaffected by CLIP. Conclusions: This is the first report demonstrating the antimicrobial efficacy of CLIP for MDROs found in infected wounds. CLIP did not compromise cultured human fibroblast growth and survival. This study demonstrated that very low fluence rates (irradiances) delivered over extended periods are potently antimicrobial. There is translational potential for CLIP to be fabricated as a wearable device that would enable continuous ambulatory care of wounds.

Regenerative Medicine to Improve Outcomes of Ventral Hernia Reconstruction (REPAIR Study) Phase 1: Find the Best Decellularization Protocol for the Human Dermis.

Background: Tissue regeneration is a complex process that allows wounds to heal. Many options are currently available to help human skin repair and to reduce the recurrence of hernias. The aim of this study is to analyze the best decellularization protocol for allogenic human dermal tissues. Methods: Dermal flaps from donors were used and compared with a control group. Each flap was subjected to seven different decellularization protocols and washed with a sequence of five solutions. The samples were then subjected to four control tests (such as Nile Red), and long-term contacts were analyzed to assess whether the decellularized dermis samples could support the growth of human fibroblasts. Results: All the samples had an average residual viability of 60%. Except for one sample, the decellularization treatments were able to reduce cell viability significantly. The Nile Red test showed a significant reduction in phospholipid content (mean 90%, p-value < 0.05) in all treatments. The cell growth increased in a linear manner. As described in the literature, sodium-dodecyl-sulfate (SDS) caused an interference between the test and the detergent. Conclusions: This paper shows the first step to finding the best decellularization protocol for allografting human dermal tissues. Further biocompatibility tests and DNA quantification are necessary.

Prognostic factors affecting periodontal regenerative therapy using recombinant human fibroblast growth factor-2: A 3-year cohort study.

IntroductionFibroblast growth factor-2 (FGF-2) has been reported to promote periodontal tissue regeneration. However, no study has investigated the long-term prognosis of periodontal regenerative therapy using FGF-2 to date. The aim of this study was to observe the long-term outcomes as well as to investigate the factors affecting the prognosis of periodontal regenerative therapy using FGF-2.MethodsSixty intrabony defects were prospectively investigated for three years after periodontal regenerative therapy with recombinant human FGF-2 (rhFGF-2) by evaluating probing pocket depth (PPD) and radiographic bone defect depth (RBD). The factors influencing RBD were assessed by conducting a multivariate linear regression analysis after adjusting for confounders.ResultsThe mean age of the participants was 62.4 ± 13.4 years, and baseline PPD and RBD were 6.1 ± 1.9 mm and 4.5 ± 1.8 mm, respectively. At six months, one year, and three years after surgery, PPD and RBD had significantly improved to 4.2 ± 1.7, 3.7 ± 1.4, 4.0 ± 1.9 mm and to 3.08 ± 2.05, 2.73 ± 1.90, 2.51 ± 2.15 mm, respectively. At the three-year examination, a significant positive association was deteced between RBD reduction and RBD at baseline, while the association was not significant between RBD reduction and the radiographic bony angle, number of bony walls of the defect, or the furcation involvement at baseline.ConclusionsrhFGF-2 was effective for alveolar bone regeneration in patients with periodontitis and maintained the improved parameters over the three-year observation period. The radiographic bone defect depth at baseline was found to be the factor affecting the periodontal regenerative therapy using rhFGF-2 in the intrabony defects.Trial registration numberUMIN000027979.

The recombinant human fibroblast growth factor-18 (sprifermin) improves tendon-to-bone healing by promoting chondrogenesis in a rat rotator cuff repair model.

Rotator cuff healing is improved by reconstructing the fibrocartilaginous structure of the tendon-to-bone enthesis. Fibroblast growth factor (FGF)-18 (sprifermin) is a well-known growth factor that improves articular cartilage repair via its anabolic effect. This study aimed to investigate the effect of recombinant human FGF-18 (rhFGF-18) on the chondrogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) invitro and tendon-to-bone healing in a rat model of rotator cuff repair. Histological and reverse transcription-quantitative real-time polymerase chain reaction analyses of chondral pellets cultured with different concentrations of rhFGF-18 were performed. Bilateral detachment and repair of the supraspinatus tendon were performed on rats. The rats were administered 0.2mL of sodium alginate (SA) hydrogel with (rhFGF-18/SA group, n=12) or without (SA group, n=12) 20μg of rhFGF-18 into the repaired side. The simple repair group (n=12) served as a control. At 4 and 8weeks after surgery, histological analysis and biomechanical tests were performed. After chondrogenesis induction, compared with the control group, 10ng/mL of rhFGF-18 increased pellet volume significantly (P=.002), with improved histological staining. It was noted that 10ng/mL of rhFGF-18 upregulated the mRNA expression (relative ratio to control) of aggrecan (2.59±0.29, P<.001), SRY-box transcription factor 9 (1.88±0.05, P<.001), and type II collagen (1.46±0.18, P=.009). At 4 and 8weeks after surgery, more fibrocartilage and cartilaginous extracellular matrix was observed in rhFGF-18/SA-treated rats. The semiquantitative data from picrosirius red staining test were 31.1±4.5 vs. 61.2±4.1 at 4weeks (P<.001) and 61.5±2.8 vs. 80.5±10.5 at 8weeks (P=.002) (control vs. rhFGF-18/SA). Ultimate failure load (25.42±3.61N vs. 18.87±2.71N at 4weeks and 28.63±5.22N vs. 22.15±3.11N at 8weeks; P=.006 and P=.03, respectively) and stiffness (18.49±1.38N/mm vs. 14.48±2.01N/mm at 8weeks, P=.01) were higher in the rhFGF-18/SA group than in the control group. rhFGF-18 promoted chondrogenesis in the hBMSCs invitro. rhFGF-18/SA improved tendon-to-bone healing in the rats by promoting regeneration of the fibrocartilage enthesis. rhFGF-18 (sprifermin) may be beneficial in improving tendon-to-bone healing after rotator cuff repair.

Therapeutic potential of recombinant human basic fibroblast growth factor on postoperative patients with chronic rhinosinusitis with nasal polyps.

To explore the effect of intranasal administration of recombinant human basic fibroblast growth factor (rh-bFGF) on postoperative chronic rhinosinusitis with nasal polyps (CRSwNP) patients. A prospective, randomised, controlled, single-blinded trial. Seventy-five hospitalised patients who met the criteria of primary bilateral CRSwNP were enrolled from March 2020 to January 2021. Visual analogue scale, 22-item Sino-Nasal Outcome Test, Lund-Kennedy (L-K) system and scanning electron microscopy and quantitative real-time polymerase chain reaction. Seventy-five patients with CRSwNP were randomly assigned to three groups, and 72 patients completed the 1-month medication regimen and 1-year follow-up. Rh-bFGF nasal-spray and drop application reduced general nasal VAS scores within 2 weeks after endoscopic sinus surgery (ESS) compared to the control group. In contrast, only rh-bFGF nasal-drops reduced SNOT-22 scores at 2 weeks and 1year compared with the control group. A significant reduction in the endoscopic L-K score was observed in the rh-bFGF nasal-spray and drop group compared with the control group. This is primarily because rh-bFGF promotes cilia growth in the nasal mucosal epithelium after the operation, as illustrated by scanning electron microscopy and expression of CP110, Tap73 and Foxj1 mRNA. For eosinophilic CRSwNP, the general VAS score of rh-bFGF nasal-drops was more obviously reduced compared to the control group after ESS. A similar trend was observed for L-K score. Rh-bFGF nasal-drops and sprays can quickly and effectively relieve postoperative symptoms and improve long-term prognosis of patients with CRSwNP. Moreover, rh-bFGF nasal-drops is also an effective method for postoperative patients with eosinophilic CRSwNP.

Effects of methacrylic anhydride gelatin hydrogel loaded with silver and recombinant human basic fibroblast growth factor on deep partial-thickness burn wounds in rabbits

Effects of methacrylic anhydride gelatin hydrogel loaded with silver and recombinant human basic fibroblast growth factor on deep partial-thickness burn wounds in rabbits

Discovering the effect of solvents on poly(2-aminoethyl methacrylate) grafting onto chitosan for an in vitro skin model

The design of controlled grafting copolymers is critical in synthesizing effective artificial cellular matrices because of their regulatory role in cellular behavior. However, it is unclear whether poly(2-aminoethyl methacrylate) grafted onto chitosan generated by gamma-radiation-induced graft polymerization in different solvents can influence the physicochemical properties and biotech applicability of the copolymer. This work aims to demonstrate for the first time the effect of various solvents on the synthesis, properties, and biological performance of grafted chitosan using the simultaneous irradiation method. The results proved that the solvent is one of the critical factors affecting the properties of the modified polysaccharide. The degree of grafting showed a solvent-dependent profile. Hexane presented utmost importance concerning the degree of grafting. Ethyl acetate showed the best results in grafting extent and human dermal fibroblast growth. These findings indicate that proper solvent selection determines the possible copolymer use for in vitro engineered skin substitute models.

Effect of fibroblasts on promoting the sprout and migration of endothelial cells in three-dimensional pre-vascularized microstructures

To construct three-dimensional (3D) pre-vascularized microstructures and explore the promoting effect of human fibroblasts (HFs) on the sprout and migration of human umbilical vein endothelial cells (HUVECs) in 3D co-culture system. HUVECs and HFs were cultured and the 3rd to 5th generation cells were selected for subsequent experiments. In 2D co-culture system, HFs were stained with PKH26 and the cell density was fixed, which co-cultured with HUVECs in different ratios (1∶4, 1∶1, 4∶1) and inoculation methods (HUVECs inoculation at 48 hours after HFs, direct mixed inoculation). Then the formation of vascular like structures was observed under fluorescence microscope. In 3D co-culture system, HUVECs and HFs were labeled with green fluorescent protein and red fluorescent protein by lentivirus transfection, respectively. They were inoculated on porous micro-carriers followed by dynamically culturing in rotating bottles to prepare HF, HUVEC, HF-EC, or HF&EC microstructures. The cell growth in microstructures was testing by low permeability crystal violet staining. Subsequently, the microstructures were embedded in fibrin gel and the cell growth and adhesion in HF and HUVEC microstructures were observed by laser confocal microscopy. Laser confocal microscope were also used to observe the sprouts of 4 kinds of microstructures, as well as the cell composition, the number and length of sprouts from HF-EC and HF&EC microstructures. HFs conditioned medium was prepared to observe its effect on sprouts of HUVEC microstructures with DMEM as control group. In 2D co-culture system, HFs pre-culturing was helpful to the formation and stability of vascular like structures, and the best effect was when the ratio of two kinds of cells was 1∶1. In 3D co-culture system, it was found that the cells grew well on micro-carriers and had the ability of pre-vascularization. HUVEC microstructures did not sprout, but HF, HF-EC, and HF&EC microstructures could which indicated a good vascularization ability. The HF-EC microstructures were superior to HF&EC microstructures in terms of sprouts length and number ( P<0.05). The tubes sprouting from co-cultured group were composed of HFs and HUVECs, and HF microstructures migration preceded HUVEC microstructures always, and their migration trajectories were the same. HUVEC microstructures could sprout when cultured in HFs conditioned media. HF-HUVEC pre-vascularized microstructures can be prepared by pre-culturing HFs before HUVECs and with the cell ratio at 1∶1 in a rotating bottle. In 3D co-culture system, HFs can promote and guide the sprout of HUVECs.

Fusion Tag Design Influences Soluble Recombinant Protein Production in Escherichia coli.

Fusion protein technologies to facilitate soluble expression, detection, or subsequent affinity purification in Escherichia coli are widely used but may also be associated with negative consequences. Although commonly employed solubility tags have a positive influence on titers, their large molecular mass inherently results in stochiometric losses of product yield. Furthermore, the introduction of affinity tags, especially the polyhistidine tag, has been associated with undesirable changes in expression levels. Fusion tags are also known to influence the functionality of the protein of interest due to conformational changes. Therefore, particularly for biopharmaceutical applications, the removal of the fusion tag is a requirement to ensure the safety and efficacy of the therapeutic protein. The design of suitable fusion tags enabling the efficient manufacturing of the recombinant protein remains a challenge. Here, we evaluated several N-terminal fusion tag combinations and their influence on product titer and cell growth to find an ideal design for a generic fusion tag. For enhancing soluble expression, a negatively charged peptide tag derived from the T7 bacteriophage was combined with affinity tags and a caspase-2 cleavage site applicable for CASPase-based fusiON (CASPON) platform technology. The effects of each combinatorial tag element were investigated in an integrated manner using human fibroblast growth factor 2 as a model protein in fed-batch lab-scale bioreactor cultivations. To confirm the generic applicability for manufacturing, seven additional pharmaceutically relevant proteins were produced using the best performing tag of this study, named CASPON-tag, and tag removal was demonstrated.

Clinical Outcomes of Periodontal Regenerative Therapy Using rhFGF-2 with a Modified Minimally Invasive Surgical Technique for Intrabony Defects: Case Series with a 12-Month Follow-up.

The Modified Minimally Invasive Surgical Technique (M-MIST) was designed to improve wound stability and reduce patient morbidity. This case series aimed to evaluate clinical outcomes of periodontal regenerative therapy using recombinant human fibroblast growth factor (rhFGF)-2 with M-MIST for the treatment of intrabony defects. Following initial periodontal therapy, nine intrabony defects in seven patients received rhFGF-2 therapy. Using M-MIST, a buccal incision was made to gain access to the defect without interdental and lingual incisions. After debridement, rhFGF-2 was applied to the defect. Periodontal parameters were evaluated at baseline and at 3, 6, and 12 months postoperatively. Composite Outcome Measure (COM) and patient-reported outcome measure (PROM, recorded using an oral health-related quality of life [QoL] instrument) were also used for evaluation. At 12 months postoperative, mean probing depth reduction was 4.2 ± 0.8 mm and clinical attachment gain was 4.7 ± 0.7 mm. The mean value for gingival recession was -0.3 ± 0.5 mm. According to COM, the outcomes of the treated sites were successful. An improvement in oral health-related QoL was noted at 12 months compared to after the initial periodontal therapy. This case series shows that rhFGF-2 therapy with M-MIST yields favorable clinical outcomes in the treatment of intrabony defects.

Construction and Validation of a Chloroplast Expression Vector for the Production of Recombinant Proteins in Chlorella vulgaris

Microalgae constitute a diverse group of photosynthetic unicellular microorganisms that have gained immense attention for biotechnological applications. They are promising platforms for the production of high-value metabolites and biopharmaceuticals for commercial and therapeutic applications because of their physiological properties and capability to grow easily in natural and artificial environments. Although the proof-of-concept for some applications have been achieved for model species, such as Chlamydomonas reinhardtii, the genetic engineering methods for microalgae are still in their infancy. Thus, an expansion of this field is required. Chlorella vulgaris is an important algal species with a high protein content and requires focus for the development of an efficient nuclear and chloroplast transformation process. This research aimed to establish a chloroplast transformation method for the freshwater green-algae species C. vulgaris based on a specific expression vector (pCMCC, which was named after Chula Mexico Chlorella chloroplast) constructed with endogenous recombination regions, namely, 16S–trn I (left) and trn A–23S (right), and the Prrn promoter. Human basic fibroblast growth factor (bFGF) was adopted as a target biopharmaceutical to establish the chloroplast expression approach. The plasmid pCMCC:bFGF was transformed into C. vulgaris via electroporation using simple carbohydrate-based buffers, which aided in the transfer of the transgene into the chloroplast genome. Cells transformed with the pCMCC:bFGF vector were selected using kanamycin, and resistant colonies were analyzed by polymerase chain reaction and Western blotting to confirm the presence of the transgene and the recombinant bFGF, respectively. The bFGF that accumulated in the transplastomic C. vulgaris clones ranged from 0.26 to 1.42 ng/g fresh weight of biomass, and it was quantified by enzyme-linked immunosorbent assay. Therefore, the designed expression vector, in combination with an optimized electroporation protocol, constitutes a viable approach to successfully develop transplastomic lines of C. vulgaris for the potential low-cost production of biopharmaceuticals using this algal species. This study paves the way for the establishment of chloroplast biotechnology in microalgae other than the model organism C. reinhardtii.

Dense high aspect ratio nanostructures for cell chip applications - Fabrication, replication, and cell interactions

Culturing human cells on the surface of a microchip brings living cells in direct contact with artificial microstructured surfaces. This work focuses on the effect of high aspect ratio nanostructures – dense nanoneedle arrays – on the mechanical response and proliferation of fibroblasts. We present a fabrication process for micropatterned chips that feature areas with hierarchical high aspect ratio nanostructures directly adjacent to flat chip areas. The chip was pre-patterned by conventional lithography. We have fabricated “black silicon” arrays of densely packed, sharp, vertical nano-needles for high aspect ratio structures by cryogenic reactive ion etching in an SF 6 /O 2 plasma. An essential requirement for many real-life applications is to make such complex high aspect ratio 3D nanostructures available in larger areas. We have successfully demonstrated the 3D replication of black silicon by a UV- nanoimprint lithography process. This study provides insight into the extent to which such nanoneedle arrays influence the growth of human fibroblasts. We have investigated microstructured samples featuring a combination of (i) smooth surfaces and (ii) nanoneedle surfaces for the mechanical behavior and proliferation of fibroblasts. Our results show that the bonding viability and proliferation of the fibroblast on the high aspect ratio nano-needle surfaces differ significantly from flat surfaces. The nanoneedles only provide a minimum area for cell attachment compared to the neighboring flat, unstructured chip areas. • Development of a fabrication process for a dense nano-needle array. • Reproduction of black silicon using nanoimprint lithography. • Black silicon structures were investigated with regard to NIL replication and cell proliferation.

Durability of and role of AKT in FGF7p urothelial protection against cyclophosphamide.

We previously identified a peptide derived from human fibroblast growth factor 7 (FGF7p) that blocks urothelial apoptosis similar to full‐length FGF7, although effects of FGF7p on urothelial repair are unknown. Also, while urothelial AKT activation downstream of FGF7p correlated with the anti‐apoptotic effects, we have not directly interrogated the role of AKT in mediating the cytoprotection. Our goal was to assess effects of FGF7p on urothelial repair and the role of AKT signaling in mediating the cytoprotective effects of FGF7p. We performed hematoxylin and eosin (H&E), TUNEL, and/or immunofluorescence (IF) staining for various markers in FGF7p‐treated mice 28 days after giving cyclophosphamide or after co‐administering a systemic AKT antagonist with FGF7p 24 h after cyclophosphamide. Vehicle‐treated and injured mice had hyperplastic urothelium, incomplete return of mature superficial cell markers, ongoing proliferation, and continued presence of basal progenitor markers 28 days after injury; conversely, FGF7p‐treated mice had normal numbers of urothelial cell layers, nearly complete return of superficial cell markers, limited proliferation and fewer basal progenitor cells 28 days post‐injury. Vehicle‐treated mice also had ectopic lumenal basal progenitor cell markers, while FGF7p had none 28 days after cyclophosphamide. Co‐administration of an AKT inhibitor largely abrogated FGF7p‐driven AKT activation and cytoprotection in urothelium 24 h after injury. Thus, FGF7p drives faster and higher fidelity urothelial repair by limiting apoptotic injury via AKT signaling, similar to full‐length FGF7. Finally, FGF7p is much less expensive to synthesize and has a longer shelf life and higher purity than FGF7.

Polydopamine modified acellular dermal matrix sponge scaffold loaded with a-FGF: Promoting wound healing of autologous skin grafts.

Despite increasing potentials as a skin regeneration template (DRT) to guide tissue healing, acellular dermal matrix (ADM) is still challenged by issues (like dense architecture, low cellular adhesion and poor vascularization), contributing to necrosis and shedding of upper transplanted skins. Modified with polydopamine (PDA), a novel and porous DRT capable of drug delivery was designed using porcine-derived ADM (PADMS) gels, termed PDA-PADMS. However, it was unclear whether it could efficiently deliver human acidic fibroblast growth factor (a-FGF) and regenerate skin defects. Herein, after being fabricated and optimized with PADMS gels in different ratios (1:6, 1:7, 1:8), PDA-PADMS loading a-FGF (PDA-PADMS-FGF) was evaluated by the morphology, physical& chemical properties, drug release and in-vitro biological evaluations, followed by full-thickness skin defects implanted with PDA-PADMS-FGF covered by transplanted skins. Apart from containing abundant collagen and elastin, porous PADMS (with a loose and uniform structure) was demonstrated to possess controlled release of a-FGF and biocompatibility attributed to PDA coating. Consistent with augmented cellular migration and proliferation in vitro, PDA-PADMS-FGF also accelerated wound healing and reduced scarring, improving collagen arrangement and neovascularization. In conclusion, PDA-PADMS-FGF has a good potential and application prospect as a matrix material for wound repair.

Design of variants of human fibroblast growth factor 1 with enhanced stability and cell proliferation activity

Human Fibroblast growth factor 1 (hFGF1) is a member of FGF1 subfamily which play significant biological roles, including cell proliferation, cell differentiation, and wound healing. Under physiological temperatures, hFGF1 has low thermodynamic stability and susceptible to the action of proteases. Circular dichroism, fluorescence spectroscopy, and other related studies reveal that reversal of charge on R136 by acidic amino acids (Glu) drastically increases the enzymatic resistance to thrombin, thermal stability, and cell proliferation activity of the growth factor. Interestingly, introduction of R136D mutation shows that the protein stability and cell proliferation activity is similar to the wild‐type protein. Microsecond molecular dynamics studies suggest that length of the side chain of acidic amino acid at position 136 is critical to confer stability to the protein. Detailed analysis of the results will be presented.

Minimal Cube Explant Provides Optimal Isolation Condition of Mesenchymal Stem Cells from Umbilical Cord.

Enzymatic digestion and explant method have been widely used for isolating umbilical cord-derived mesenchymal stem cells (UC MSCs), although there is still a strong need for robust protocols for optimal isolation for large-scale stem cell banks. This study aims to establish an explant method for clinical scale production of MSCs from human UC tissue and to characterize UC MSCs isolated and cultured with the explant method. UC MSCs were isolated by enzymatic digestion, minimal cube explant (MCE) 1-2, MCE 2-4, and MCE 10 and cultured, respectively. Also, human antibody array and basic fibroblast growth factor (bFGF) secretion in conditioned medium (CM) was analyzed. The cells were evaluated initial cell number, colony forming unit-fibroblast (CFU-F), proliferation capacity, CD marker expression, and multi-lineage differentiation. SA-β-gal assay as well as expression of p16, p21 and p53 was performed by RT-PCR. MCE 2-4 is the most optimized method for isolation of small umbilical cord-derived fast proliferating cells (smumf cells) with the greatest number. MCE 2-4 had the highest secretion of various bioactive factors including bFGF. The MCE 2-4 provided significantly higher CD146 expression than enzymatic digestion, and that expression was maintained until P20. The gene expression of p16, p21, and p53 of smumf cells did not change until P10 and SA-β-gal activity did not increase until P14. This study demonstrated that MCE 2-4 provided an optimal environment to isolate MSCs with quantity and quality from human whole UC tissue through secretion of various bioactive factors inherent to UC.

Synthesis and Properties of α-Mangostin and Vadimezan Conjugates with Glucoheptoamidated and Biotinylated 3rd Generation Poly(amidoamine) Dendrimer, and Conjugation Effect on Their Anticancer and Anti-Nematode Activities.

α-Mangostin and vadimezan are widely studied potential anticancer agents. Their biological activities may be improved by covalent bonding by amide or ester bonds with the third generation poly(amidoamine) (PAMAM) dendrimer, substituted with α-D-glucoheptono-1,4-lactone and biotin. Thus, conjugates of either ester- (G3gh4B5V) or amide-linked (G32B12gh5V) vadimezan, and equivalents of α-mangostin (G3gh2B5M and G32B12gh5M, respectively), were synthesized, characterized and tested in vitro against cancer cells: U-118 MG glioma, SCC-15 squamous carcinoma, and BJ normal human fibroblasts growth, as well as against C. elegans development. α-Mangostin cytotoxicity, stronger than that of Vadimezan, was increased (by 2.5–9-fold) by conjugation with the PAMAM dendrimer (with the amide-linking being slightly more effective), and the strongest effect was observed with SCC-15 cells. Similar enhancement of toxicity resulting from the drug conjugation was observed with C. elegans. Vadimezan (up to 200 µM), as well as both its dendrimer conjugates, was not toxic against both the studied cells and nematodes. It showed an antiproliferative effect against cancer cells at concentrations ≥100 µM. This effect was significantly enhanced after conjugation of the drug with the dendrimer via the amide, but not the ester bond, with G32B12gh5V inhibiting the proliferation of SCC-15 and U-118 MG cells at concentrations ≥4 and ≥12 μM, respectively, without a visible effect in normal BJ cells. Thus, the drug delivery system based on the PAMAM G3 dendrimer containing amide bonds, partially-blocked amino groups on the surface, larger particle diameter and higher zeta potential can be a useful tool to improve the biological properties of transported drug molecules.

Mechanical performance and cyocompatibility of PU/PLCL nanofibrous electrospun scaffolds for skin regeneration

Skin tissue engineering with considerable skin regeneration capability is an urgent need for the wound site. The current challenge for researchers is to develop a bionic scaffold that imitates the extracellular matrix for the regeneration of the damaged regions. In our study, poly(L-lactide-co-caprolactone) (PLCL) was blended with polyurethane (PU) to obtain nanofibrous scaffolds via electrospinning. The electrospun fibers with 50% PLCL content had a certain number of intersections and jointing points, and exhibited significantly enhanced mechanical properties combined with suitable porosity. Moreover, cell activities demonstrated that PU/PLCL membranes had significantly biological advantages in enhanced growth of human skin fibroblasts with spreading morphology compared with PU membranes, indicating good cytocompatibility of composite scaffolds. These findings proved that PU/PLCL electrospun membranes have great potential in applications of skin tissue engineering.