A novel multifunctional chitosan-gelatin/carboxymethyl cellulose-alginate bilayer hydrogel containing human placenta extract for accelerating full-thickness wound healing

The replication of skin's dermal and epidermal morphology within a full-thickness wound using a bi-layer hydrogel to cater to their distinct needs is a compelling pursuit. Moreover, human placenta extract (HPE), containing a diverse array of bioactive agents, has proven to be effective in promoting the wound healing process and enhancing epidermal keratinocytes. This study presents a multifunctional bi-layer hydrogel incorporating HPE for accelerating full-thickness wound healing through sustained HPE release, inhibition of bacteria invasion, and promotion of cell proliferation. The upper layer of the scaffold, known as the dressing layer, is composed of carboxymethyl cellulose and sodium alginate, serving as a supportive layer for cell proliferation. The under layer, referred to as the regenerative layer, is composed of chitosan and gelatin, providing an extracellular matrix-like, porous, moist, and antibacterial environment for cell growth. The scaffold was optimized to replicate the morphology of the dermal and epidermal layers, with suitable fibroblast infiltration and a pore size of approximately 283μm. Furthermore, the degradation rate of the samples matched the wound healing rate and persisted throughout this period. The sustained HPE release rate, facilitated by the degradation rate, was optimized to reach ~98% after 28 days, covering the entire healing period. The samples demonstrated robust antibacterial capabilities, with bacterial inhibition zone diameters of and 2.63±0.12cm for S. aureus and E. coli, respectively. The biocompatibility of the samples remained at approximately 68.33±4.5% after 21 days of fibroblast cell culture. The in vivo experiment indicated that the HPE@Bilayer hydrogel promotes the formation of new blood vessels and fibroblasts during the early stages of healing, leading to the appropriate formation of granulation tissue and a wound contraction rate of (79.31±3.1)%. Additionally, it resulted in the formation of a thick epidermal layer (keratinization) that effectively covered all the impaired areas, achieving a wound contraction rate of 95.83±6.3% at the late stage of wound healing. Furthermore, immunohistochemistry staining for CD31 and TGF-β revealed that the HPE@Bilayer group had 22 blood vessels/field and 34%-66% immunoactive cells, respectively, after 14 days of healing. However, by day 21, angiogenesis and TGF-β expression had declined, demonstrating that the wounds had been successfully treated with minimal scarring.

Human placental extract suppresses mast cell activation and induces mast cell apoptosis

BACKGROUND

Human placental extract (HPE) has been documented to facilitate the healing of certain disorders including allergy. However, the effects of HPE on the functionality of mast cells, a critical cell type in allergic diseases, have not been reported.

METHODS

To investigate the effects of HPE on the regulation of allergy with respect to the biological functions of mast cells, the mast cell line C57 or HMC-1 cells were treated with HPE followed by the assessment of cell proliferation, apoptosis, activation, chemotaxis and phagocytosis. Mouse peritoneal mast cells were also investigated for their responses to induction of apoptosis by HPE in vivo. Furthermore, the effect of HPE on mast cell degranulation was confirmed using the passive cutaneous anaphylaxis (PCA) assay, an acute allergy model.

RESULTS

HPE was capable of suppressing mast cell proliferation and inducing mast cell apoptosis. Mast cell degranulation in response to compound 48/80- or anti-DNP IgE and DNP-mediated activation was suppressed. In addition, treatment with HPE compromised the production of cytokines by mast cells and cell chemotaxis. These observations were consistent with the dampened passive cutaneous anaphylaxis (PCA) assay following treatment with HPE.

CONCLUSION

This study revealed a suppressive effect of HPE on overall mast cell activities, suggesting a potential regulatory role of HPE on the alleviation of allergic diseases through mast cells.

Frequently used strategies to isolate ECM proteins from human placenta and adipose tissue

BACKGROUND

The natural extracellular matrix (ECM) provides the optimal environment for cells. Many enzymatic or non-enzymatic based strategies to extract ECM proteins from tissues were published over the last years. However, every single isolation strategy reported so far is associated with specific bottlenecks. Experiment: In this study, frequently used strategies to isolate extracellular matrix (ECM) from human placenta or adipose tissue using Tris-, serum, or pepsin-based buffers were compared. The resulting ECM proteins were biochemically characterized by analysis of cellular remnants using HOECHST DNA staining, glycosaminoglycan (GAG) content by dimethylemethylene blue (DMMB), visualization of protein bands using SDS PAGE analysis combined with amino acid quantification and assessment of the pro-angiogenic profile using an angiogenesis array.

RESULTS

Tris-NaCl extracted ECM proteins showed a high heterogenic degree of extracted proteins, bioactive growth factors and GAGS, but no collagen-I. Active serum extracted ECM showed significant lower DNA remnants when compared to the Tris-NaCl isolation strategy. Pepsin-extracted ECM was rich in collagen-I and low amounts of remaining bioactive growth factors. This strategy was most effective to reduce DNA amounts when compared to the other isolation strategies. Pepsin-extracted ECM from both tissues easily gelled at 37°C, whereas the other extracted ECM strategies did not gel at 37°C (Tris-NaCl: liquid; serum: sponge).

CONCLUSIONS

All relevant characteristics (DNA residues, ECM diversity and bioactivity, shape) of the extracted ECM proteins highly depend on its isolation strategy and could still be optimized.

Novel Human Placenta-Based Extract for Vascularization Strategies in Tissue Engineering

There is critical unmet need for new vascularized tissues to support or replace injured tissues and organs. Various synthetic and natural materials were already established for use of two-dimensional (2D) and three-dimensional (3D) in vitro neovascularization assays, however, they still cannot mimic the complex functions of the sum of the extracellular matrix (ECM) in native intact tissue. Currently, this issue is only addressed by artificial products such as Matrigel^™, which comprises a complex mixture of ECM proteins, extracted from animal tumor tissue. Despite its outstanding bioactivity, the isolation from tumor tissue hinders its translation into clinical applications. Since nonhuman ECM proteins may cause immune reactions, as are frequently observed in clinical trials, human ECM proteins represent the best option when aiming for clinical applications. Here, we describe an effective method of isolating a human placenta substrate (hpS) that induces the spontaneous formation of an interconnected network of green fluorescence-labeled human umbilical vein endothelial cells (gfpHUVECs) in vitro. The substrate was biochemically characterized by using a combination of bicinchoninic acid (BCA) assay, DNA, and glycosaminoglycan (GAG) content assays, sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) analysis and Western blot, angiogenesis arrays, chromatographic thrombin detection, high performance liquid chromatography (HPLC)-based amino acid quantification analysis, and assessment of antimicrobial properties. 2D in vitro cell culture experiments have been performed to determine the vasculogenic potential of hpS, which demonstrated that cell networks developed on hpS show a significantly higher degree of complexity (number of tubules/junctions; total/mean tube length) when compared with Matrigel. As 3D cell culture techniques represent a more accurate representation of the in vivo condition, the substrate was 3D solidified using various natural polymers. 3D in vitro vasculogenesis assays have been performed by seeding gfpHUVECs in an hpS-fibrinogen clot. In conclusion, hpS provides a potent human/material-based alternative to xenogenic-material-based biomaterials for vascularization strategies in tissue engineering.

COLLAGEN: STRUCTURE, METABOLISM, PRODUCTION AND INDUSTRIAL APPLICATION

This review presents the current scientific literature data about structure, properties, and functions of collagen, which is known as one of the most abundant human and animal proteins. The building of collagen molecule from the primary structure to submolecular formations, the main stages of its synthesis and biodegradation are briefly described. The information about collagen diversity, its features and metabolic ways in various tissues, including skin, tendons, bones, etc. is presented. The problems of pathologies caused by collagen synthesis and breakdown disorders as well as age-related changes in collagen properties and their causes are discussed. A comparative analysis of the advantages and disadvantages of collagen and its derivatives obtaining from various sources (animals, marine, and recombinant) is given. The most productive methods for collagen extraction from various tissues are shown. The concept of collagen hydrolysis conditions influence on the physicochemical properties and biological activity of the obtained products is described. The applications of collagen and its products in various fields of industrial activity, such as pharmaceutical, cosmetic industry and medicine, are discussed. Further prospective directions of fundamental and applied investigations in this area of research are outlined.

PVA and PCL nanofibers are suitable for tissue covering and regeneration

The aim of the study was to evaluate the safety and efficacy of a new therapeutic approach to skin defects resulting from split thickness grafting. Within the study, nanofiber-based dressings fabricated using polyvinyl alcohol (PVA) and poly-ε-caprolactone (PCL) were used, with different mass density. The study was performed in 1 female minipig. Nine defects (approx. 4x4 cm) were made in the superficial skin layer. The tested materials were applied to the squared skin defect and covered by a Jelonet paraffin gauze, sutured in the corners of the defects. The animal was monitored daily during the healing process (21 days). On day 5, 12, and 27, the healing of the wound was evaluated, and a biopsy was performed for further histologic testing. At the end of the study (on day 27 after the procedure), the animal was euthanized, and a standard pathologic evaluation was performed. We can conclude that the nanofiber scaffold which was well tolerated, could be used as a smart skin cover which could be functionalized with another bioactive substances directly on the surgeon table, among potential bioactive substances belong platelet derivatives, antibiotics, etc.

Effect of human placental extract in the management of biofilm mediated drug resistance - A focus on wound management

Management of infectious wounds, particularly chronic wounds and burn injuries, is a matter of global concern. Worldwide estimates reveal that, billions of dollars are being spent annually for the management of such chronic ailments. Evidently, bacterial biofilms pose a greater problem in the effective management of infection in chronic wounds, since most of the currently available antibiotics are unable to act on the microorganisms residing inside the protected environment of the biofilms. Accordingly, in the present study, we have attempted to evaluate the anti-biofilm properties of human placental extract (PLX) and also other virulence factors that are mediated via the quorum sensing (QS) signalling system. PLX is well known for its anti inflammatory action and it has been shown earlier some anti microbial and enzymatic activity also. PLX was found to produce significant inhibition of biofilm formation and also decreased the levels of pyoverdin and pyocyanin. The microscopic analysis (both light microscopy and atomic force microscopy) of biofilms was also used for substantiating the findings from spectrophotometric (crystal violet estimation) and fluorescence analysis (resazurin uptake). PLX pre-treatment decreased the hydrophobicity of gram-positive and gram negative cells, indicating the effect of placental extract on adherence property of planktonic cell, serving as an indicator for its antibiofilm effect on microorganisms. The reduced extracellular DNA (eDNA) content in biofilm matrix following treatment with PLX also indicates the effectiveness of placenta extract on bacterial adherence, which in turn serves as evidence substantiating the antibiofilm effects of the PLX. Furthermore, PLX was also found to be significantly effective in the in vitro wound biofilm model. Thus the present study, the first of its kind with PLX, establishes the therapeutic benefit of the same particularly in infected wounds, opening up newer avenue for further exploration.

Biochemical and functional analysis of corticotropin releasing factor purified from an aqueous extract of human placenta used as wound healer

Human placental extract constitutes of innumerable therapeutically important components mostly used in wound healing arising from the skin and burn injuries. However, there is still some bioactive present in the placental extracts yet to be characterized to better under the complex process of wound healing mediated by the placental extract. In this study, the presence of corticotropin releasing factor (CRF) in an aqueous extract of human placenta was detected and quantified by dot blot and CRF-ELISA immunoassay kit respectively. Subsequently, it was purified by immuno-affinity chromatography and quantified as 0.45±0.05μg of CRF per ml of placental extract where its molecular weight found to be 4.78kDa by MALDI-TOF. To study functional analysis of CRF, an in vitro WI-38 lung fibroblast cell scratch wound model was used which indicated proliferation, motility of cells after treatment with purified CRF. Moreover, reduction in apoptosis rate of cells during closure of wound was observed from microscopy studies and FACS analysis. Also, Antalarmin, an antagonist of CRF type 1 receptor inhibited the wound closure potency of the purified component. Faster healing of wound with an elevation of IL-6 and TGF-β during early stages of repair by placental CRF was observed on excision rat model. The process of healing was accompanied by the decrease in the level of TNF-α and IFN-γ.

Hominis Placenta facilitates hair re-growth by upregulating cellular proliferation and expression of fibroblast growth factor-7

Background

Hominis Placenta (HP) known as a restorative medicine in Traditional Chinese Medicine (TCM), has been widely applied in the clinics of Korea and China as an anti-aging agent to enhance the regeneration of tissue. This study was conducted to investigate whether topical treatment of HP promotes hair regrowth in the animal model.

Methods

The dorsal hairs of 8-week-old C57BL/6 mice were depilated to synchronize hair follicles to the anagen phase. HP was applied topically once a day for 15 days. Hair growth was evaluated visually and microscopically. The incorporation of bromodeoxyuridine (BrdU) and expression of proliferating cell nuclear antigen (PCNA), fibroblast growth factor-7 (FGF-7) in dorsal skin tissue was examined by immunohistochemical analysis. Reverse transcription polymerase chain reaction (RT-PCR) was used to measure the mRNA expression of FGF-7.

Results

HP exhibited potent hair growth-promoting activity in C57BL/6 mice. Gross examination indicated that HP markedly increased hair regrowth as well as hair density and diameter. Histologic analysis showed that HP treatment enhanced the anagen induction of hair follicles.

Immunohistochemical analysis revealed that BrdU incorporation and the expressions of PCNA were increased by treatment of HP. HP treatment significantly increased the expression of FGF-7, which plays pivotal roles to maintain anagen phase both protein and mRNA levels.

Conclusions

Taken together, our results indicate that HP has a potent hair growth-promoting activity; therefore, it may be a good candidate for the treatment of alopecia.

Effect of new neuronal growth factor on healing of sciatic nerve in rats

OBJECTIVE

The study aimed to investigate the effect of a new peptide new nerve growth factor (NNGF) on the healing of divided sciatic nerves in rats.

MATERIAL AND METHODS

Twenty Sprague-Dawley rats of 250-300g were divided into two groups (group 1 - study group and group 2 - control group). Under ketamine intramuscular anesthesia sciatic nerves were exposed, divided and repaired using 10/0 dexon. Study animals had 10mg/kg body weight of NNGF added to the repair. Electromyographic studies of the hind libs were carried out after 8weeks. The average stimulation was 50mA for 200μS and four twitches (T) were recorded. The animals were euthanized and the sciatic nerves were removed for histological analysis.

RESULTS

There were no deaths in either of the groups. Electromyographic study showed that in the control group the average T1-T4 was 0.587±0.17% and in the study group the average was 87.89±5.02% (p value of 0.001). Histologically the control group showed regenerated axons sprouting from the proximal segment of cut nerve with empty endoneurial channels, while in the study group whole nerve trunks were seen within endoneurial channels.

CONCLUSION

This study shows that the NNGF has a positive influence on the experimental healing of sciatic nerves in animals.

Effects of Porcine Placenta Extract Ingestion on Ultraviolet B-induced Skin Damage in Hairless Mice

The aim of our study was to evaluate the potential benefits of an oral supplement containing porcine placenta extract (PPE) on skin parameters related to cutaneous physiology and aging. PPEs were administered orally to hairless mice for 12 wk. The effects of oral PPE administration on skin water-holding capacity and Transepidermal Water Loss (TEWL) were similar to those of oral collagen (HYCPU2) administered as a positive control. Magnified photographs and replica images showed a reduction in UVB-induced wrinkle formation after collagen and PPE treatments. PPE treatments ameliorated the thicker skin surface that results from UVB exposure, based on a histological examination of skin tissue. The groups that were orally administered PPE (0.05%, OL; 0.1%, OH group) showed significantly reduced Matrix Metaloproteinase-2 (MMP-2) mRNA expression levels compared with the UVB control (Con), by 33.5% and 35.2%, respectively. The mRNA expression of another collagen-degrading protein, MMP-9, was also significantly lower in the groups that received oral administration of PPE (especially in the OH group) than in the control group. Additionally, oral administration of PPE significantly upregulated tissue inhibitor of metalloproteinase-1 (TIMP-1) and -2 mRNA expression levels compared with expression levels in the control group (p<0.05). This indicates that orally administered PPE activated the expression of Timp-1 and -2, inhibitors of MMP, which is responsible for collagen degradation in skin. Taken together, we propose that long-term oral administration of PPE might have a beneficial effect with respect to skin photo-aging.

Ubiquitin-like protein from human placental extract exhibits collagenase activity

An aqueous extract of human placenta exhibits strong gelatinase/collagenase activity in zymography. 2-D gel electrophoresis of the extract with gelatin zymography in the second dimension displayed a single spot, identified as ubiquitin-like component upon MALDI/TOF MS/MS analysis. Immunoblot indicated presence of ubiquitin and absence of collagenase in the extract. Collagenase activity of the ubiquitin-like component was confirmed from the change in solubility of collagen in aqueous buffer, degradation of collagen by size-exclusion HPLC and atomic force microscopy. Quantification with DQ-gelatin showed that the extract contains 0.04 U/ml of collagenase activity that was inhibited up to 95% by ubiquitin antibody. Ubiquitin from bovine erythrocytes demonstrated mild collagenase activity. Bioinformatics studies suggest that placental ubiquitin and collagenase follow structurally divergent evolution. This thermostable intrinsic collagenase activity of placental extract might have wide physiological relevance in degrading and remodeling collagen as it is used as a drug for wound healing and pelvic inflammatory diseases.

Development and evaluation of fiber optic probe-based helium-neon low-level laser therapy system for tissue regeneration--an in vivo experimental study

We report the design and development of an optical fiber probe-based Helium-Neon (He-Ne) low-level laser therapy system for tissue regeneration. Full thickness excision wounds on Swiss albino mice of diameter 15 mm were exposed to various laser doses of 1, 2, 3, 4, 6, 8 and 10 J cm(-2) of the system with appropriate controls, and 2 J cm(-2) showing optimum healing was selected. The treatment schedule for applying the selected laser dose was also standardized by irradiating the wounds at different postwounding times (0, 24 and 48 h). The tissue regeneration potential was evaluated by monitoring the progression of wound contraction and mean wound healing time along with the hydroxyproline and glucosamine estimation on wound ground tissues. The wounds exposed to 2 J cm(-2) immediately after wounding showed considerable contraction on days 5, 9, 12, 14, 16 and 19 of postirradiation compared with the controls and other treatment schedules, showing significant (P < 0.001) decrease in the healing time. A significant increase in hydroxyproline and glucosamine levels was observed for the 2 J cm(-2) irradiation group compared with the controls and other treatment groups. In conclusion, the wounds treated with 2 J cm(-2) immediately after the wounding show better healing compared with the controls.