Hiroshi Mizuno

Background: Chronic limb-threatening ischemia (CLTI) is a severe condition associated with high mortality and amputation rates, particularly in patients with diabetes, renal failure, or severe vascular disease. In cases where revascularization fails or is not possible, adjunctive therapies can improve the treatment outcomes. Therefore, this single-center retrospective study aimed to evaluate the effectiveness of low-density lipoprotein/fibrinogen apheresis (Rheocarna^®) in promoting wound healing in patients with no-option CLTI, focusing on large wounds. Methods: We examined the data of 32 CLTI ulcers treated with Rheocarna^® from 2021 to 2024. Results: The outcomes in 25 cases (78.1%) were rated as excellent or good, and the outcomes of 11 (73.3%) wound, ischemia, and foot infection (WIfI) wound-3 ulcers were excellent or good. Overall, 75% of the CLTI ulcers achieved wound healing without major amputation. Predictive factors for successful wound healing included age, baseline skin perfusion pressure, and wound grade (WIfI classification). A skin perfusion pressure threshold of 28.5 mmHg (WIfI ischemic grade 3) was a significant predictor of positive outcomes. Conclusions: Our results support the use of Rheocarna^® as a viable adjunctive therapy in managing refractory large ischemic ulcers and preventing major amputations.

Recently, cell based therapy become a popular topic in research fields. This therapy offers great potential to treat many diseases. Adipose-derived stem cell (ASCs) is known to have the special characteristic due to its abundant availability and easily harvesting. Then it rapidly advanced into clinical trials for treatment of a broad range of medical conditions. Before translating ASCs from bench to bedside, this process is facing other problems through fetal bovine serum (FBS) elimination. Animal-derived serum is not a suitable option for ASCs expansion regarding the possibility of viral or bacterial infection and immune reaction. By replacing FBS with other non-animal serum which gives the same effect as FBS, may significantly enhances the safety and quality of ASCs. Pooled human AB serum (AB-HS), human serum (HS), pooled human plasma lysate (PL), umbilical cord serum (UCS)/placental serum (PS), thrombinactivated platelet rich plasma (tPRP) or serum free (SF)/xeno-free (XF) have been considered as FBS alternatives and some already applied in clinical trials with human cells. This article focuses on a prospective alternatives serum through the elimination of FBS.

Summary: Necrotizing fasciitis (NF) type I is an acute subcutaneous tissue infection that can promptly disseminate generating crepitus. If not accurately diagnosed and expeditiously treated, it becomes a life-threatening infection. In this report, we present a 65-year-old man who developed a case of NF after a hemiglossectomy resecting a tumor in the dorsal surface of the tongue. A biopsy was performed, and he was pathologically diagnosed with squamous cell carcinoma (T2N1M0). The patient underwent preoperative oral cleaning. Right hemiglossectomy was performed by cervical dissection, pull-through style, with tooth removal on the right mandible and a left anterolateral femoral flap reconstruction. Routine intraoperative lavage was performed with 2000 mL of saline solution. Cefazolin 1gr was administered two times per day postoperatively. Four days after primary surgery, the flap circulation was inadequate; therefore, a computed tomography scan was taken, which indicated gas in the ventral neck area. Tooth extraction was the suspected etiology. Debridement was performed; the abscess was drained and cultured, indicating the presence of Staphylococcus haemolyticus and Escherichia coli. It seems that the abscess was not formed by NF, but rather by leachate reservoir associated with the head and neck tumor. After debridement, re-reconstruction was performed with a deltopectoral flap and pectoralis major myocutaneous flap. When NF is present after a neck dissection, there is a risk of disruption due to the direct invasion and inflammation into the carotid artery. Therefore, it is important to provide adequate oral cleaning care before the surgery and early suspicion of the diagnosis.

A major symptom of diabetes mellitus (DM) is unfit hyperglycemia, which leads to impaired wound healing. It has been reported that the migration of fibroblasts can be suppressed under high glucose (HG) conditions. In our previous study, we introduced a serum-free culture method for mononuclear cells (MNCs) called quantity and quality control culture (QQc), which could improve the vasculogenic and tissue regeneration ability of MNCs. In this study, we described a culture model in which we applied a high glucose condition in human dermal fibroblasts to simulate the hyperglycemia condition in diabetic patients. MNC-QQ cells were cocultured with fibroblasts in this model to evaluate its role in improving fibroblasts dysfunction induced by HG and investigate its molecular mechanism. It was proven in this study that the impaired migration of fibroblasts induced by high glucose could be remarkably enhanced by coculture with MNC-QQ cells. PDGF B is known to play important roles in fibroblasts migration. Quantitative PCR revealed that MNC-QQ cells enhanced the gene expressions of PDGF B in fibroblasts under HG. Taken with these results, our data suggested a possibility that MNC-QQ cells accelerate wound healing via improving the fibroblasts migration and promote the gene expressions of PDGF B under diabetic conditions.

The quality and quantity of endothelial progenitor cells (EPCs) are impaired in patients with diabetes mellitus patients, leading to reduced tissue repair during autologous EPC therapy. This study aimed to address the limitations of the previously described serum-free Quantity and Quality Control Culture System (QQc) using CD34+ cells by investigating the therapeutic potential of a novel mononuclear cell (MNC)-QQ. MNCs were isolated from 50 mL of peripheral blood of patients with diabetes mellitus and healthy volunteers (n = 13 each) and subjected to QQc for 7 days in serum-free expansion media with VEGF, Flt-3 ligand, TPO, IL-6, and SCF. The vascular regeneration capability of MNC-QQ cells pre- or post-QQc was evaluated with an EPC colony-forming assay, FACS, EPC culture, tube formation assay, and quantitative real time PCR. For in vivo assessment, 1 × 104 pre- and post-MNC-QQc cells from diabetic donors were injected into a murine wound-healing model using Balb/c nude mice. The percentage of wound closure and angio-vasculogenesis was then assessed. This study revealed vasculogenic, anti-inflammatory, and wound-healing effects of MNC-QQ therapy in both in vitro and in vivo models. This system addresses the low efficiency and efficacy of the current naïve MNC therapy for wound-healing in diabetic patients. As this technique requires a simple blood draw, isolation, and peripheral blood MNC suspension culture for only a week, it can be used as a simple and effective outpatient-based vascular and regenerative therapy for patients with diabetes mellitus.

Many bone regeneration therapies have been developed for clinical use and have variable outcomes and serious limitations. The goal of bone regeneration is to repair a bone defect in a stable and durable manner. Cellular strategies play an important role in bone tissue engineering. Clinical factors important for successful bone regeneration are the recruitment of cells to the defect site and the production of a suitable extracellular matrix consistent with bone tissues. Adipose-derived stem cells (ASCs) can be obtained in large quantities with little donor site morbidity or patient discomfort. They are multipotent somatic stem cells and have a strong potential to differentiate and secrete growth factors. In this review, we discuss the osteogenic potential of ASCs with/without several types of scaffolds in vivo and their clinical application for bone regeneration.