Bioinspired RGD-Engineered Bacteriophage Nanofiber Cues against Oxidative Stress.

Instructive tissue engineering biomaterials provide a vascular niche and protect oxidative stress in injured tissue. In this study, we exploited bioinspired bacteriophage nanofibers, previously recognized by their biochemical and structural cues inducing angiogenesis, as an antioxidant tissue engineering material. We demonstrated that topological cues of Arg-Gly-Asp (RGD)-engineered bacteriophage nanofibers provide angiogenic niches and cytoprotective functions against cellular oxidative stress with increased expression of antioxidant enzymes heme oxygenase-1 (HO-1) and NAD(P)H-quinone oxidoreductase 1 (NQO1) via the extracellular-signal-regulated kinase (ERK)-nuclear factor erythroid 2-related factor2 (Nrf2)-mediated signaling pathway, where a high density of RGD cues on the phage body support efficient interaction of cells with phage cues. These bioinspired RGD-engineered bacteriophage nanofibers can serve as a novel therapeutic platform for curing ischemic diseases.

Biomimetic virus-based soft niche for ischemic diseases.

The essential therapeutic cues provided by a nanofibrous arginine-glycine-aspartic acid-engineered M13 phage were exploited as extracellular matrix (ECM)-mimicking niches, contributing to de novo soft tissue niche engineering. The interplay of biomimetic phage cues with surrounding organ tissues was identified, and cells were implanted between tissues to achieve an appropriate soft tissue niche that enables the proper functioning of the implanted stem cells at the injured site. With the polyacrylamide (PA) hydrogel mimicking the soft tissue organ stiffness ranges, it was found that biochemical and topological cues in conjunction with the ∼1-2 kPa elastic and mechanical cues of engineered phage nanofibers in soft tissues efficiently enhance the desired response of implanted stem cells. This phage cue with angiogenic and antioxidant functions overcomes the pathological environment to support implanted cells and surrounding soft tissues at the ischemic site, thereby successfully decreasing myogenic degeneration, minimizing fibrosis, and enhancing blood vessel regeneration with M2 macrophage polarization by improving the survival of the implanted endothelial progenitor cells (EPC) in an ischemic mouse model. These biomimetic phage nanofiber cues are considerably supportive of cell therapy, as they establish promising therapeutic extracellular de novo soft tissue niches for curing ischemic diseases.

Phage-Based Artificial Niche: The Recent Progress and Future Opportunities in Stem Cell Therapy.

Self-renewal and differentiation of stem cells can be the best option for treating intractable diseases in regenerative medicine, and they occur when these cells reside in a special microenvironment, called the "stem cell niche." Thus, the niche is crucial for the effective performance of the stem cells in both in vivo and in vitro since the niche provides its functional cues by interacting with stem cells chemically, physically, or topologically. This review provides a perspective on the different types of artificial niches including engineered phage and how they could be used to recapitulate or manipulate stem cell niches. Phage-based artificial niche engineering as a promising therapeutic strategy for repair and regeneration of tissues is also discussed.

Correction: Engineered phage nanofibers induce angiogenesis.

Correction for 'Engineered phage nanofibers induce angiogenesis' by So Young Yoo et al., Nanoscale, 2017, 9, 17109-17117.

Stem Cells Seeded on Multilayered Scaffolds Implanted into an Injured Bladder Rat Model Improves Bladder Function.

Background: To investigate whether human adipose-derived stem cells (hADSCs) seeded on multilayered poly (l-lactide-co-ɛ-caprolactone) (PLCL) sheets improve bladder function in a rat model of detrusor smooth muscle-removed bladder. Methods: Male rats were randomly divided into 4 groups: Normal, injury (detrusor smooth muscle-removed bladder), PLCL (detrusor smooth muscle-removed bladder implanted with PLCL sheets), and PLCL + ADSC (detrusor smooth muscle-removed bladder implanted with PLCL sheets seeded with hADSCs). Four weeks after the treatment, physiological, histological, immunohistochemical, and immunoblot analyses were performed. Results: hADSCs were compatible with PLCL sheets. Further, the physiological study of PLCL + ADSC group showed significant improvement in compliance and contractility suggesting the functional improvement of the bladder. Histological, immunohistochemical and immunoblot analyses revealed the uniform distribution of hADSCs in between PLCL sheets as well as differentiation of hADSCs into smooth muscle cells (SMC) which is illustrated by the expression of SMC markers. Conclusion: hADSCs seeded on the multilayered PLCL sheets has the potential to differentiate into SMC, thus facilitating the recovery of compliance and contractility of the injured bladder.

Engineered phage nanofibers induce angiogenesis.

Herein, we exploited a bioinspired M13 bacteriophage as an angiogenic nanofiber for soft tissue engineering applications. We demonstrated that engineered phage nanofibers induce angiogenesis with specific biochemical and topological cues. Specifically, nanofibrous phage structures provided a novel therapeutic platform for stem cell technologies in ischemic diseases.

Combination Therapy Using Human Adipose-derived Stem Cells on the Cavernous Nerve and Low-energy Shockwaves on the Corpus Cavernosum in a Rat Model of Post-prostatectomy Erectile Dysfunction.

OBJECTIVE: To investigate combined therapeutic efficacy of human adipose-derived stem cells (h-ADSCs) application on injured cavernous nerve and low-energy shockwave therapy (SWT) on the corpus cavernosum in a rat model of post-prostatectomy erectile dysfunction. MATERIALS AND METHODS: Rats were randomly divided into 5 groups: control, bilateral cavernous nerve injury (BCNI), adipose-derived stem cell (ADSC) (BCNI group with h-ADSCs on the cavernous nerve), SWT (BCNI group with low-energy SWT on the corpus cavernosum), and ADSC/SWT (BCNI group with a combination of h-ADSCs and low-energy SWT). After 4 weeks, erectile function was assessed using intracavernosal pressure. The cavernous nerves and penile tissue were evaluated through immunostaining, Western blotting, and a cyclic guanosine monophosphate assay. RESULTS: ADSC/SWT significantly improved intracavernosal pressure compared to the other experimental group. ADSC had significantly increased ß-III tubulin expression of the cavernous nerve, and SWT had a markedly enhanced vascular endothelial growth factor expression in corpus cavernosum. The ADSC/SWT group had a significantly increased in alpha smooth muscle actin content (P < .05), neural nitric oxide synthase (nNOS) of the dorsal penile nerve (P < .05), endothelial nitric oxide synthase (eNOS) protein expression (P < .05), and cyclic guanosine monophosphate level (P < .05) compared to the ADSC or SWT alone group. In addition, ADSC/SWT reduces the apoptotic index in the corpus cavernosum. CONCLUSION: In this study, h-ADSCs showed an effect on the recovery of injured cavernous nerve and low-energy SWT improved angiogenesis in the corpus cavernosum. The h-ADSCs combined with low-energy SWT showed beneficial effect on the recovery of erectile function in a rat model of postprostatectomy erectile dysfunction.

Nanoengineered Polystyrene Surfaces with Nanopore Array Pattern Alters Cytoskeleton Organization and Enhances Induction of Neural Differentiation of Human Adipose-Derived Stem Cells.

Human adipose-derived stem cells (hADSCs) can differentiate into various cell types depending on chemical and topographical cues. One topographical cue recently noted to be successful in inducing differentiation is the nanoengineered polystyrene surface containing nanopore array-patterned substrate (NP substrate), which is designed to mimic the nanoscale topographical features of the extracellular matrix. In this study, efficacies of NP and flat substrates in inducing neural differentiation of hADSCs were examined by comparing their substrate-cell adhesion rates, filopodia growth, nuclei elongation, and expression of neural-specific markers. The polystyrene nano Petri dishes containing NP substrates were fabricated by a nano injection molding process using a nickel electroformed nano-mold insert (Diameter: 200 nm. Depth of pore: 500 nm. Center-to-center distance: 500 nm). Cytoskeleton and filopodia structures were observed by scanning electron microscopy and F-actin staining, while cell adhesion was tested by vinculin staining after 24 and 48 h of seeding. Expression of neural specific markers was examined by real-time quantitative polymerase chain reaction and immunocytochemistry. Results showed that NP substrates lead to greater substrate-cell adhesion, filopodia growth, nuclei elongation, and expression of neural specific markers compared to flat substrates. These results not only show the advantages of NP substrates, but they also suggest that further study into cell-substrate interactions may yield great benefits for biomaterial engineering.

Comparison between subcutaneous injection of basic fibroblast growth factor-hydrogel and intracavernous injection of adipose-derived stem cells in a rat model of cavernous nerve injury.

OBJECTIVE: To compare the effects of subcutaneous penile injection of basic fibroblast growth factor (bFGF)-hydrogel and intracavernous injection of human adipose-derived stem cells (h-ADSCs) on improving erectile function in a rat model of cavernous nerve injury. MATERIALS AND METHODS: Adult male Sprague-Dawley rats were randomly divided into 5 groups (n = 10 per group): age-matched control (normal group), bilateral cavernous nerve injury (BCNI group), penile subcutaneous injection of hydrogel after BCNI (hydrogel group), penile subcutaneous injection of bFGF-hydrogel after BCNI (bFGF-hydrogel group) and intracavernous injection of h-ADSCs after BCNI (ADSC group). Four weeks after the treatment, all rats underwent an erectile function test. Then, penile tissue was harvested for immunohistological analysis of bFGF, phalloidin, and cluster of differentiation (CD) 31. The cyclic guanosine monophosphate (cGMP) level of the corpus cavernosum was quantified by cGMP assay. RESULTS: From the functional test and immunohistological result, we observed that bFGF-hydrogel and h-ADSCs injection significantly elevated intracavernous pressure. The evaluation of filamentous actin content, CD31 expression, and cGMP concentration in the corpus cavernosum were meaningfully increased in the bFGF-hydrogel and ADSC groups compared with BCNI group. The bFGF released from bFGF-hydrogel prevented smooth muscle atrophy. Moreover, bFGF expression was significantly increased in bFGF-hydrogel group. CONCLUSION: The subcutaneous injection of bFGF-hydrogel prevented smooth muscle atrophy, increased the intracavernous pressure, and improved erectile function like an intracavernous injection of h-ADSCs.

The effect of PnTx2-6 protein from Phoneutria nigriventer spider toxin on improvement of erectile dysfunction in a rat model of cavernous nerve injury.

OBJECTIVE: To explore the therapeutic potential of PnTx2-6 injected 3 times a week for 4 weeks into the intracavernosal tissue in a rat model of bilateral cavernous nerve crush injury (BCNI). METHODS: Eight-week-old male Sprague-Dawley rats were randomly divided into the following 6 groups (n = 5 per group): age-matched control (normal group), BCNI (injury group), post-BCNI phosphate-buffered saline injection (PBS group), post-BCNI Sf9 cell-lysate injection (N/C group), post-BCNI injection of cell lysate from S9 cells infected with wild-type recombinant baculovirus (W/T group), and post-BCNI injection of cell lysate from S9 cells infected with recombinant baculovirus containing PnTx2-6 (PnTx2-6 group). Injections were delivered 3 times a week for 4 weeks. After 4 weeks, intracavernosal pressure-to-mean arterial pressure ratio, smooth muscle and collagen content via the Masson trichrome staining, levels of neural nitric oxide synthase, phosphoendothelial nitric oxide synthase, and cyclic guanosine monophosphate were all measured. RESULTS: The PnTx2-6 group showed significantly higher intracavernosal pressure-to-mean arterial pressure ratio (P <.05), smooth muscle-to-collagen ratio (P <.01), expression levels of neural nitric oxide synthase, phosphoendothelial nitric oxide synthase (P <.05), and cyclic guanosine monophosphate (P <.05) than all other experimental groups. CONCLUSION: We conclude that PnTx2-6 improved erectile function and prevented muscle atrophy in a rat model of BCNI via increased synthesis of nitric oxide and cyclic guanosine monophosphate.

Combined effects of brain-derived neurotrophic factor immobilized poly-lactic-co-glycolic acid membrane with human adipose-derived stem cells and basic fibroblast growth factor hydrogel on recovery of erectile dysfunction.

Erectile dysfunction (ED) is the most frequent long-term problem after radical prostatectomy. We aimed to evaluate whether the use of combination therapy with basic fibroblast growth factor (bFGF)-hydrogel on corpus cavernosum and with adipose-derived stem cells (ADSCs) and brain-derived neurotrophic factor (BDNF)-immobilized poly-lactic-co-glycolic acid (PLGA) membrane on the cavernous nerve (CN) could improve erectile function in a rat model of bilateral cavernous nerve crush injury (BCNI). Rats were randomly divided into five groups (n=15 per group): a normal group (N group), a group receiving saline application after bilateral cavernous nerve crush injury (BCNI), a group undergoing bFGF-hydrogel injection in the corpus cavernosum after BCNI (bFGF), a group receiving ADSC application covered with BDNF-membrane after BCNI (ADSC/BDNF), and a group undergoing coadministration of bFGF-hydrogel injection and BDNF-membrane with ADSCs after BDNF (bFGF+ADSC/BDNF). Four weeks postoperatively, the erectile function was assessed by detecting the ratio of intracavernous pressure (ICP) to mean arterial pressure (MAP). Smooth muscle and collagen contents were measured using Masson's trichrome staining. Neuronal nitric oxide synthase (nNOS) expression in the dorsal penile nerve was detected by immunostaining. The protein expression of the α-smooth muscle actin (α-SMA) and the cyclic guanosine monophosphate (cGMP) level of the corpus cavernosum were quantified by western blot and cGMP assay, respectively. In the bFGF+ADSC/BDNF group, the erectile function was significantly elevated compared with the BCNI and other treated groups and showed a significantly increased smooth muscle/collagen ratio, nNOS content, α-SMA expression, and cGMP level. In particular, there were no statistical differences in the ICP/MAP ratio, smooth muscle/collagen ratio, and α-SMA and cGMP levels between the bFGF+ADSC/BDNF group and normal group. Application of the BDNF-immobilized PLGA membrane with human ADSC into the CN and bFGF-incorporated hydrogel into the corpus carvernosum improved nearly normal erectile function in a rat model of postprostatectomy ED. This result suggests that a combined application of bFGF+ADSC/BDNF might be a promising treatment for postprostatectomy ED.