Superficial acral fibromyxoma: insights from case management and comprehensive literature review.

Superficial acral fibromyxoma, also known as digital fibromyxoma, is a slow-growing, benign, solitary soft tissue tumor. First described in 2001 by Fetsch et al., it is a condition that often occurs in middle-aged individuals. However, it has also been reported across a wide range of ages, ranging from 4 to 86 years, with males more commonly reported. The condition often presents as solitary soft tissue swelling over the periungual or subungual. We present the management experience of the rare presentation of this rare tumor and a detailed review of the past literature on this condition. Detailed management of the condition has been described, along with the outcome after 2 years of follow-up and treatment experience. Our detailed analysis shows that 2 years is the shortest duration of follow-up to rule out recurrence. Hence, most of the cases reported earlier had given the false sense of the recurrence rate of the tumor, which could lead to undertreatment of the condition. The purpose of this article is to allow the readers to understand better the tumor's characteristics with bone involvement and the tumor's diagnostic strategies and treatment options.

Flexor tendon degeneration affects short-term outcomes of open trigger digit release.

We aimed to investigate the association between flexor tendon degeneration and outcome of open trigger digit release. We recruited 162 trigger digits (136 patients) who had open trigger digit release from February 2017 to March 2019. Intraoperatively, six features of tendon degenerations were identified: irregular tendon surface, tendon fraying, intertendinous tear, synovial thickening, hyperaemia of sheath and tendon dryness. Longer duration of preoperative symptoms was associated with worsening tendon surface irregularity and fraying; increased number of steroid injections was associated with worsening tendon surface irregularity and dryness; higher DASH score was associated with severe tendon fraying, dryness and intertendinous tear; limited proximal interphalangeal joint (PIPJ) motion was associated with severe tendon dryness. At 1-month post-surgery, DASH score remained high in severe intertendinous tear group while PIPJ motion remained limited in severe tendon dryness group. In conclusion, the severity of various flexor tendon degenerations influenced the outcome of open trigger digit release at 1-month but did not affect the outcome at 3- and 6-months post-surgery.

Video-assisted thoracoscopic surgery (VATS) aided full-length phrenic nerve transfer for restoration of elbow flexion.

BACKGROUND: In complete brachial plexus injury, phrenic nerve (PN) is frequently used in neurotization for elbow flexion restoration. The advancement in video-assisted thoracoscopic surgery (VATS) allows full-length PN dissection intrathoracically for direct coaptation to recipient without nerve graft. PURPOSE: We report our experience in improving the surgical technique and its outcome. METHODS: Seven patients underwent PN dissection via VATS and full-length transfer to musculocutaneous nerve (MCN) or motor branch of biceps (MBB) from June 2015 to June 2018. Comparisons were made with similar group of patients who underwent conventional PN transfer. RESULTS: Mean age of patients was 21.9 years. All were males involved in motorcycle accidents who sustained complete brachial plexus injury. We found the elbow flexion recovery were earlier in full-length PN transfer. However, there was no statistically significant difference in elbow flexion strength at 3 years post-surgery. CONCLUSION: We propose full-length PN transfer for restoration of elbow flexion in patients with delayed presentation.

The Outcome of Moderate-to-Severe Complications Related to Peripheral Intravenous Devices at Upper Limb.

Background: Intravenous access is very crucial in administration of fluids, medications and nutrition. Almost all inpatients will require it and the simplest and quickest access is peripheral with the preferred sites being either dorsum hand, radial wrist or forearm. It has its complications, of which most are avoidable. Literature has emphasised the complications and reported on preventive measures but lacks the sequelae of the complications related to peripheral intravenous devices (PIVD). We report on the sequelae of moderate-to-severe complications of these patients. Methods: Thirty-three patients had moderate-to-severe complications related to PIVD in a tertiary centre from January 2017 to December 2017. All data were obtained from electronic medical report (EMR). Results: Majority had extravasation (45.5%) and abscess (39.4%), whereas two patients had thrombophlebitis (6.1%) and three patients developed necrotising fasciitis (9.1%). All patients with abscess and necrotising fasciitis underwent surgical intervention (n = 16); four patients had multiple debridements. All infections were treated with empirical antibiotics and changed after culture results were obtained. Seven patients had sepsis/bacteraemia wherein two of them passed away. A total of 31 patients were discharged. Two patients had secondary suturing of the wound, one had split-thickness skin grafting (SSG) coverage and the others had daily dressing until the wound healed by secondary intention. Conclusions: PIVD-related complications can be debilitating and may occur despite strict preventive measures. Early clinical diagnosis and prompt treatment of these complications can decrease its morbidity. Level of Evidence: Level IV (Prognostic).

Reliability of WhatsApp images of plain radiographs to diagnose fractures of the hand and wrist.

We assessed the reliability of plain radiographs interpreted through WhatsApp messaging system in orthopaedic hand trauma consultation in a large teaching hospital. Plain radiographs of 25 hand fractures and five normal radiographs were captured from a picture archiving and communication system using iPhone XS smartphone, anonymized and sent to 53 orthopaedic residents' and consultants' personal smartphones. The participants independently assessed the images and answered questions on fracture identification and characteristics, diagnostic confidence, further imaging and surgical inclination. The study was repeated after a 1-month washout period using the picture archiving and communication system on the hospital desktop. The results showed good (0.60 < ƙ < 0.80) intraobserver agreement on fracture identification and characteristics. The overall diagnostic accuracy for hand fractures was 95% on WhatsApp and 99% on the desktop. In conclusion, images of plain radiographs transmitted via WhatsApp were reliable for interpretation in orthopaedic hand trauma consultation.Level of evidence: IV.

TGF-ß1 and -ß3 for Mesenchymal Stem Cells Chondrogenic Differentiation on Poly (Vinyl Alcohol)-Chitosan-Poly (Ethylene Glycol) Scaffold.

Transforming growth factor-beta 1 (TGF-ß1) has been reported to promote chondrogenic differentiation and proliferation in the multipotent stromal cell (MSCs), and the transforming growth factor-beta 3 (TGF-ß3) tends to be exclusively in promoting cell differentiation alone. The objective of this study was to determine the effect of TGF-ß1 and -ß3 on the MSCs chondrogenic differentiation on the poly (vinyl alcohol)-chitosan-poly (ethylene glycol) (PVA-NOCC-PEG) scaffold, compared with that of monolayer and pellet cultures. In this study, P2 rabbit bone marrow-derived MSCs were seeded either on the untreated six-well plate (for monolayer culture) or onto the PVA-NOCC-PEG scaffold or cultured as a pellet culture. The cultures were maintained in a chemically defined serum-free medium supplemented with 10 ng/mL of either TGF-ß1 or TGF-ß3. Cell viability assay, biochemical assay, and real-time polymerase chain reaction were performed to determine the net effect of cell proliferation and chondrogenic differentiation of each of the growth factors. The results showed that the PVA-NOCC-PEG scaffold enhanced MSCs cell proliferation from day 12 to 30 (p < 0.05); however, no significant differences were observed in the cell proliferation between the cultures supplemented with or without TGF-ß1 and TGF-ß3 (p > 0.05). In terms of chondrogenic differentiation, the PVA-NOCC-PEG scaffold augmented the GAGs secretion in MSCs and the mRNA expression levels of Sox9, Col2a1, Acan, and Comp were elevated (p < 0.05). However, there was no significant difference between both the TGF-ß1 and TGF-ß3-treated groups (p > 0.05). In conclusion, TGF-ß1 and TGF-ß3 enhanced the chondrogenic differentiation of MSCs seeded on the PVA-NOCC-PEG scaffold; however, there was no significant difference between the effect of TGF-ß1 and TGF-ß3. Impact statement Transforming growth factor-beta (TGF-ß) superfamily members is a key requirement for the in vitro chondrogenic differentiation of mesenchymal stem cells (MSCs). In this study, the effects of TGF-ß1 and -ß3 on MSC chondrogenic differentiation and proliferation on a novel three-dimensional scaffold, the poly(vinyl alcohol)-chitosan-poly(ethylene glycol) (PVA-NOCC-PEG) scaffold, was evaluated. In this study, the results showed both TGF-ß1 and TGF-ß3 can enhance the chondrogenic differentiation of MSCs seeded on the PVA-NOCC-PEG scaffold.

Upper limb infections: A comparison between diabetic and non-diabetic patients.

BACKGROUND: Upper limb infections are common among patients with diabetes mellitus and their sequelae can be debilitating. They tend to present with severe infections but minimal symptoms probably due to neuropathy and vasculopathy among diabetics. The study aims to compare the demographic characteristics, clinical presentations and outcomes of upper limb infections between diabetic and non-diabetic patients. METHODS: All patients with upper limb infections who were admitted in a tertiary hospital from June 2017 to December 2020 were included in this study. Demographic data, clinical presentations, investigations and outcomes were obtained retrospectively from electronic medical record. There were 117 patients with diabetes mellitus and 127 with no diabetes mellitus. Comparisons were made between these two groups, and statistical analysis was done with SPSS. RESULTS: There were 244 patients included; 117 were diabetic and 127 were non-diabetic. Diabetic patients were more likely to present with emergent scenarios, especially necrotizing fasciitis and infective tenosynovitis (p < .05) with higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) readings (p < .05). Their microbiological cultures were less likely to be negative (p < .05). Diabetic patients also had poorer clinical outcomes with higher risk of amputation, re-operation and longer duration of hospital stay (p < .05). CONCLUSION: Upper limb infections among diabetic patients should be treated aggressively. Early diagnosis and surgical intervention might decrease the morbidity and mortality in this group. Prevention of infections should be emphasized.

Clinical outcome of Maggot Debridement Therapy followed by Negative Pressure Wound Therapy for chronic hand wound with Multi-Drug Resistant Organism infection: Two cases and review of the literature.

The advancement in science and research has led to development of medical maggots which feed exclusively on dead tissue. Medical maggots have three important functions namely debridement, disinfection, and stimulation of wound healing. The modern use of medical maggots now goes by the term "Maggot Debridement Therapy" (MDT) for use in wound management. MDT is still used infrequently due to the effectiveness of surgical debridement and antibiotics for treatment of wound infection. Lately, there was emergence of Multi-Drug Resistant Organism (MDRO) likely due to inappropriate antibiotics usage. Maggot secretions have been shown to be effective in inhibiting some MDRO, for example, Methicillin-resistant Staphylococcus aureus, thus making MDT an attractive option for wounds with MDRO. We report two patients with multiple medical comorbidities, diagnosed with serious MDRO Diabetic Hand Infections treated with three cycles of MDT followed by Negative Pressure Wound Therapy.

Hand Surgery in Malaysia.

We have all heard the old aphorism, "Necessity is the mother of invention." While the provenance of the proverb is uncertain, its truth is not in doubt. This is true for the development of hand surgery in Malaysia. As part of the management for leprosy, patients with high ulnar nerve palsies were managed by the pioneers of hand surgery in Malaysia. They did tendon transfers to improve the quality of life of these patients. Since then, hand surgery in Malaysia have grown leaps and bounds. From a small humble beginning in the suburb of Sungai Buloh to organizing the 10th Congress of Asian Pacific Federation of Societies for Surgery of the Hand, hand surgery in Malaysia will only get better with time.

A Novel Supraretinacular Endoscopic Carpal Tunnel Release: Surgical Technique, Clinical Efficacy and Safety (A Series of 48 Consecutive Cases).

Purpose: Endoscopic carpal tunnel release has been shown to have a shorter recovery period than open surgery. This study was aimed at assessing the efficacy and possible clinical complications of a novel supraretinacular endoscopic carpal tunnel release technique. Methods: A total of 50 cases involving 46 patients were evaluated in this prospective study, in which all surgeries were performed by a single surgeon between 2016 and 2018. The patients were evaluated preoperatively; at 3, 7, and 14 days after surgery; and at 1, 3, and 6 months after surgery. The effectiveness of the surgery was evaluated using pinch and grip strengths, modified table test, visual analog scale pain score, the Disabilities of the Arm, Shoulder and Hand, the Boston Carpal Tunnel Questionnaire symptom severity scale, and the Boston Carpal Tunnel Questionnaire functional status scale. The Friedman test and Wilcoxon signed-rank test were used for a statistical analysis. Results: At 6 months after the surgery, all measured parameters showed improvements. The pinch strength score improved from 2.29 kg before the surgery to 2.96 kg 6 months after the surgery (P = .003), the grip strength score improved from 12.10 kg to 13.98 kg (P = .028), the modified table test score increased from 6.55 kg to 8.76 kg (P < .001), the visual analog scale score decreased from 6.31 to 0.52 (P < .001), the Disabilities of the Arm, Shoulder and Hand score reduced from 41.66 to 14.10 (P < .001), and the Boston Carpal Tunnel Questionnaire symptom severity scale and the Boston Carpal Tunnel Questionnaire functional status scale scores reduced from 2.68 to 1.51 (P < .001) and from 2.56 to 1.44 (P < .001), respectively. There were no serious injuries or complications reported in this series. Conclusions: This new supraretinacular endoscopic carpal tunnel release technique was shown to be efficacious in this series. Type of study/level of evidence: Therapeutic IV.

A comparison of delta wire technique versus extension block pinning in the treatment of bony Mallet finger.

ZIEL: Diese Studie vergleicht die klinischen Ergebnisse nach Delta-Draht-Technik (Gruppe 1 = 7 Patienten) mit den Ergebnissen nach Extensions-Block-Pinning (Gruppe 2 = 11 Patienten) in der Behandlung des knöchernen Mallet-Fingers. PATIENTEN UND METHODEN: Sechs Monate postoperativ wurde bei allen Patienten das klinische Ergebnis nach den Crawford-Kriterien, die Schmerzen anhand einer visuellen Analogskale (VAS) und der DASH-Score ermittelt. Zusätzlich wurden die aktive Beweglichkeit und das Extensionsdefizit im Endgelenk sowie aufgetretene Komplikationen festgehalten. ERGEBNISSE: Patienten der Gruppe 1 hatten eine signifikant bessere Beugung im Fingerendgelenk, aber auch ein signifikant größeres Extensionsdefizit, obwohl sie signifikant früher ihre Arbeit wiederaufnahmen. Nach den Crawford-Kriterien erzielten 71 % der Patienten der Gruppe 1 und 100 % der Gruppe 2 ein exzellentes und gutes Ergebnis. Keine Unterschiede konnten bzgl. der OP-Dauer, der Schmerzen, dem DASH-Score und der Zeit bis zur knöchernen Heilung festgestellt werden. SCHLUSSFOLGERUNG: In der Kurzzeitbeobachtung werden mit Extension-Block-Pinning bessere Ergebnisse in der Behandlung des knöchernen Strecksehnenausriss am Fingerendglied erzielt als mit der Delta-Draht-Technik.

Nail bed and flap reconstructions for acute fingertip injuries - A case review and report of a chemical burn injury.

Nail bed injuries were commonly found concomitantly with fingertip injuries. Reconstruction of fingertip including the nail bed should be attempted at acute stage. Aim of the surgery was to restore as much finger length and achieve normal nail growth. In chemical burns, the initial presentation might not reflect the exact extent of injury. Appropriate acute management must be initiated while waiting for demarcation. We report a case of young stewardess who presented with fingertip chemical burn injury. Surgical debridement was done on third day post-injury. A cross-finger flap to cover skin defect and split-thickness nail bed grafting from the remnant of injured finger were done. Excellent functional and cosmetic outcome was achieved in 6 months. Surgical treatment in a chemical burn was similar to traumatic injury. Nail bed graft was the best option for nail bed reconstruction. In cases of soft tissue loss, advancement or pedicle flaps are beneficial.

Short-term clinical outcome of orthosis alone vs combination of orthosis, nerve, and tendon gliding exercises and ultrasound therapy for treatment of carpal tunnel syndrome.

STUDY DESIGN: Prospective randomized study. INTRODUCTION: Carpal tunnel syndrome (CTS) has been described as the most common compression neuropathy. Many modalities exist for conservative treatment. Efficacy of each modality has been described in the literature. However, the effectiveness of combination of these modalities is not well established. The purpose of this study is to assess the short-term clinical outcome of conservative treatment for CTS comparing orthosis alone with combination of orthosis, nerve/tendon gliding exercises, and ultrasound therapy. METHODS: Forty-one patients who presented to Upper Limb Reconstructive and Microsurgery Clinic, University Malaya Medical Centre with CTS and positive electrodiagnostic study were recruited. Fifteen patients had bilateral CTS. Fifty-six wrists were equally randomized to orthosis alone and a combined therapy of orthosis, nerve/tendon gliding exercise, and ultrasound therapy. All patients were required to complete the Boston Carpal Tunnel Questionnaire during the first visit and 2 months after treatment. RESULTS: Both the orthosis and combined therapy groups showed a significant improvement in symptoms and function after treatment. The mean difference of symptoms in the orthosis group was 0.53; 95% confidence interval [CI]: 0.23-0.83 (P = .001) and in the combined therapy group was 0.48; 95% CI: 0.24-0.72 (P < .001). Mean difference of function in the orthosis group was 0.59; 95% CI: 0.28-0.91 (P = .001) and combined group was 0.69; 95% CI: 0.49-0.89 (P < .001). However, there was no significant difference in symptom severity and functional status scores between the groups. DISCUSSION: Our findings support other findings where orthosis and exercises improved symptom severity and functional status scores, however, there was no significant difference between orthosis alone and combined treatment. CONCLUSION: Patients who underwent conservative management for CTS showed improvement in symptoms and function. However, the combination of orthosis, nerve/tendon gliding exercises, and ultrasound therapy did not offer additional benefit compared to orthosis alone.

Perceived comfort during minor hand surgeries with wide awake local anaesthesia no tourniquet (WALANT) versus local anaesthesia (LA)/tourniquet.

PURPOSE: Minor hand surgeries can be done under field sterility in procedure rooms. Surgeons are still sceptical about the usage of wide awake local anaesthesia no tourniquet (WALANT) technique. They perceive that patients can tolerate tourniquet for a brief period while they perform minor surgeries under local anaesthesia (LA). We compared the perceived comfort experienced by patients during minor hand surgeries with WALANT and LA/tourniquet. We investigated the difference in preoperative preparation time, operating time and blood loss between the two groups. METHODS: Between July and October 2016, a total of 72 patients were diagnosed with carpal tunnel syndrome, trigger finger or ganglion, at the University Malaya Medical Centre. Forty patients consented to participate in this study and were randomized into WALANT and LA/tourniquet groups. Anaesthesia was administered accordingly and tourniquet was applied. The time taken for preoperative preparation and surgery was recorded. Each surgeon estimated the blood loss. The perceived comfort level of each patient was quantified using a visual analogue score (VAS). Data were analysed using SPSS. RESULTS: The mean VAS for the WALANT group was 2.33 ± 1.94, whereas it was 4.72 ± 3.05 for the LA/tourniquet group, and the difference was statistically significant ( p < 0.05). The mean time for preoperative preparation in WALANT group was 19.17 ± 12.61 min and LA/tourniquet group was 7.05 ± 3.44 min. The difference between these groups was statistically significant ( p < 0.01). There was no significant difference in operating time and blood loss. CONCLUSION: WALANT technique was associated with better patient comfort. Tourniquet was the main reason for discomfort during surgeries. WALANT is an alternative in minor hand surgeries for a bloodless surgical field without the discomfort of tourniquet application.

Stonefish envenomation of hand with impending compartment syndrome.

BACKGROUND: Marine stings and envenomation are fairly common in Malaysia. Possible contact to various marine life occurs during diving, fishing and food handling. Even though majority of fish stings are benign, there are several venomous species such as puffer fish, scorpion fish, lionfish, stingray and stonefish that require urgent medical treatment. Stonefish is one of the most venomous fish in the world with potential fatal local and systemic toxicity effects to human. CASE PRESENTATION: We reported a case of stonefish sting complicated with impending compartment syndrome. CONCLUSIONS: Medical staff should be alert about the possibility of this potential emergency in standard management of stonefish stings.

Ultra-structural changes and expression of chondrogenic and hypertrophic genes during chondrogenic differentiation of mesenchymal stromal cells in alginate beads.

Chondrogenic differentiation of mesenchymal stromal cells (MSCs) in the form of pellet culture and encapsulation in alginate beads has been widely used as conventional model for in vitro chondrogenesis. However, comparative characterization between differentiation, hypertrophic markers, cell adhesion molecule and ultrastructural changes during alginate and pellet culture has not been described. Hence, the present study was conducted comparing MSCs cultured in pellet and alginate beads with monolayer culture. qPCR was performed to assess the expression of chondrogenic, hypertrophic, and cell adhesion molecule genes, whereas transmission electron microscopy (TEM) was used to assess the ultrastructural changes. In addition, immunocytochemistry for Collagen type II and aggrecan and glycosaminoglycan (GAG) analysis were performed. Our results indicate that pellet and alginate bead cultures were necessary for chondrogenic differentiation of MSC. It also indicates that cultures using alginate bead demonstrated significantly higher (p < 0.05) chondrogenic but lower hypertrophic (p < 0.05) gene expressions as compared with pellet cultures. N-cadherin and N-CAM1 expression were up-regulated in second and third weeks of culture and were comparable between the alginate bead and pellet culture groups, respectively. TEM images demonstrated ultrastructural changes resembling cell death in pellet cultures. Our results indicate that using alginate beads, MSCs express higher chondrogenic but lower hypertrophic gene expression. Enhanced production of extracellular matrix and cell adhesion molecules was also observed in this group. These findings suggest that alginate bead culture may serve as a superior chondrogenic model, whereas pellet culture is more appropriate as a hypertrophic model of chondrogenesis.

Identification of Pathways Mediating Growth Differentiation Factor5-Induced Tenogenic Differentiation in Human Bone Marrow Stromal Cells.

To date, the molecular signalling mechanisms which regulate growth factors-induced MSCs tenogenic differentiation remain largely unknown. Therefore, a study to determine the global gene expression profile of tenogenic differentiation in human bone marrow stromal cells (hMSCs) using growth differentiation factor 5 (GDF5) was conducted. Microarray analyses were conducted on hMSCs cultures supplemented with 100 ng/ml of GDF5 and compared to undifferentiated hMSCs and adult tenocytes. Results of QuantiGene® Plex assay support the use and interpretation of the inferred gene expression profiles and pathways information. From the 27,216 genes assessed, 873 genes (3.21% of the overall human transcriptome) were significantly altered during the tenogenic differentiation process (corrected p<0.05). The genes identified as potentially associated with tenogenic differentiation were ARHGAP29, CCL2, integrin alpha 8 and neurofilament medium polypeptides. These genes, were mainly associated with cytoskeleton reorganization (stress fibers formation) signaling. Pathway analysis demonstrated the potential molecular pathways involved in tenogenic differentiation were: cytoskeleton reorganization related i.e. keratin filament signaling and activin A signaling; cell adhesion related i.e. chemokine and adhesion signaling; and extracellular matrix related i.e. arachidonic acid production signaling. Further investigation using atomic force microscopy and confocal laser scanning microscopy demonstrated apparent cytoskeleton reorganization in GDF5-induced hMSCs suggesting that cytoskeleton reorganization signaling is an important event involved in tenogenic differentiation. Besides, a reduced nucleostemin expression observed suggested a lower cell proliferation rate in hMSCs undergoing tenogenic differentiation. Understanding and elucidating the tenogenic differentiation signalling pathways are important for future optimization of tenogenic hMSCs for functional tendon cell-based therapy and tissue engineering.

Total cell pooling in vitro: an effective isolation method for bone marrow-derived multipotent stromal cells.

In vitro cellular proliferation and the ability to undergo multilineage differentiation make bone marrow-derived multipotent stromal cells (MSCs) potentially useful for clinical applications. Several methods have been described to isolate a homogenous bone marrow-derived MSCs population; however, none has been proven most effective, mainly due to their effects on proliferation and differentiation capability of the isolated cells. It is hypothesized that our newly established total cell pooling method may provide a better alternative as compared to the standard isolation method (density gradient centrifugation method). For the total cell pooling method, MSCs were isolated from rabbit bone marrow and were subsequently cultured in the growth medium without further separation as in the standard isolation method. The total cell pooling method was 65 min faster than the standard isolation method in completing cell isolation. Nevertheless, both methods did not differ significantly in the number of primary viable cells and population doubling time in the cultures (p > 0.05). The isolated cells from both methods expressed CD29 and CD44 markers, but not CD45 markers. Furthermore, they displayed multilineage differentiation characteristics of chondroblasts, osteoblasts, and adipocytes. In conclusion, both methods provide similar efficiency in the isolation of rabbit bone marrow-derived MSCs; however, the total cell pooling method is technically simpler and more cost effective than the standard isolation method.

Supermacroporous poly(vinyl alcohol)-carboxylmethyl chitosan-poly(ethylene glycol) scaffold: an in vitro and in vivo pre-assessments for cartilage tissue engineering.

This study aims to pre-assess the in vitro and in vivo biocompatibility of poly(vinyl alcohol)-carboxylmethyl-chitosan-poly(ethylene glycol) (PCP) scaffold. PCP was lyophilised to create supermacroporous structures. 3-(4, 5-dimethyl-thiazol-2yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and immunohistochemistry (IHC) were used to evaluate the effectiveness of PCP scaffolds for chondrocytes attachment and proliferation. The ultrastructural was assessed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Extracellular matrix (ECM) formation was evaluated using collagen type-II staining, glycosaminoglycan (GAG) and collagen assays. Histological analysis was conducted on 3-week implanted Sprague-Dawley rats. The MTT, IHC, SEM and TEM analyses confirm that PCP scaffolds promoted cell attachment and proliferation in vitro. The chondrocyte-PCP constructs secreted GAG and collagen type-II, both increased significantly from day-14 to day-28 (P < 0.05). PCP scaffolds did not elicit any adverse effects on the host tissue, but were partially degraded. These results suggest that supermacroporous PCP is a biocompatible scaffold for clinical applications.

Isolation, characterization and the multi-lineage differentiation potential of rabbit bone marrow-derived mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are recognized by their plastic adherent ability, fibroblastic-like appearance, expression of specific surface protein markers, and are defined by their ability to undergo multi-lineage differentiation. Although rabbit bone marrow-derived MSCs (rbMSCs) have been used extensively in previous studies especially in translational research, these cells have neither been defined morphologically and ultrastructurally, nor been compared with their counterparts in humans in their multi-lineage differentiation ability. A study was therefore conducted to define the morphology, surface marker proteins, ultrastructure and multi-lineage differentiation ability of rbMSCs. Herein, the primary rbMSC cultures of three adult New Zealand white rabbits (at least 4 months old) were used for three independent experiments. rbMSCs were isolated using the gradient-centrifugation method, an established technique for human MSCs (hMSCs) isolation. Cells were characterized by phase contrast microscopy observation, transmission electron microscopy analysis, reverse transcriptase-polymerase chain reaction (PCR) analysis, immunocytochemistry staining, flow cytometry, alamarBlue(®) assay, histological staining and quantitative (q)PCR analysis. The isolated plastic adherent cells were in fibroblastic spindle-shape and possessed eccentric, irregular-shaped nuclei as well as rich inner cytoplasmic zones similar to that of hMSCs. The rbMSCs expressed CD29, CD44, CD73, CD81, CD90 and CD166, but were negative (or dim positive) for CD34, CD45, CD117 and HLD-DR. Despite having similar morphology and phenotypic expression, rbMSCs possessed significantly larger cell size but had a lower proliferation rate as compared with hMSCs. Using established protocols to differentiate hMSCs, rbMSCs underwent osteogenic, adipogenic and chondrogenic differentiation. Interestingly, differentiated rbMSCs demonstrated higher levels of osteogenic (Runx2) and chondrogenic (Sox9) gene expressions than that of hMSCs (P < 0.05). There was, however, no difference in the adipogenic (Pparγ) expressions between these cell types (P > 0.05). rbMSCs possess similar morphological characteristics to hMSCs, but have a higher potential for osteogenic and chondrogenic differentiation, despite having a lower cell proliferation rate than hMSCs. The characteristics reported here may be used as a comprehensive set of criteria to define or characterize rbMSCs.