Raman spectroscopy for postmortem interval estimation of human skeletal remains: A scoping review.

Estimating postmortem intervals (PMI) is crucial in forensic investigations, providing insights into criminal cases and determining the time of death. PMI estimation relies on expert experience and a combination of thanatological data and environmental factors but is prone to errors. The lack of reliable methods for assessing PMI in bones and soft tissues necessitates a better understanding of bone decomposition. Several research groups have shown promise in PMI estimation in skeletal remains but lack valid data for forensic cases. Current methods are costly, time-consuming, and unreliable for PMIs over 5 years. Raman spectroscopy (RS) can potentially estimate PMI by studying chemical modifications in bones and teeth correlated with burial time. This review summarizes RS applications, highlighting its potential as an innovative, nondestructive, and fast technique for PMI estimation in forensic medicine.

Extracellular matrix mimicking scaffold promotes osteogenic stem cell differentiation: A new approach in osteoporosis research.

BACKGROUND: Osteoporosis is a common metabolic disease, with mesenchymal stem cells discussed to play an important role in its pathomechanism. For in vitro osteoporosis studies, selection of adequate culture conditions is mandatory so as to preserve cell properties as far as possible. A suitable cell culture surface would ideally provide reproducible experimental conditions by resembling those in-vivo. OBJECTIVE: Generating an improved growth surface for osteogenic differentiation of human bone marrow derived mesenchymal stem cells (hBMSCs). METHODS: We modified electrospun gelatine meshes with hydroxyapatite nanopowder. The potential beneficial impact of the ensuing culture conditions were evaluated by cultivating and comparing the growth of cells from osteoporotic and non-osteoporotic donors on either hydroxyapatite-gelatine (HA) meshes, pure gelatine meshes, or 2D standard tissue culture surfaces. RESULTS: After 21 days of differentiation, cells grown on pure or HA-gelatine meshes showed significantly higher mineralization levels compared to cells cultured in standard conditions. The amount of mineralization varied considerably in hBMSC cultures of individual patients but showed no significant difference between stem cells obtained from osteoporotic or non-osteoporotic donors. CONCLUSIONS: Overall, these results indicate that the use of HA-gelatine meshes as growth surfaces may serve as a valuable tool for cultivation and differentiation of mesenchymal stem cells along the osteogenic lineage, facilitating future research on osteoporosis and related issues.

[Masquelet technique for the treatment of large dia- and metaphyseal bone defects]. / Die Masquelet-Technik zur Behandlung großer dia- und metaphysärer Knochendefekte.

OBJECTIVE: Treatment of large dia- and metaphyseal bone defects (> 3 cm) with two surgical interventions with an interval of 4-8 weeks. INDICATIONS: Dia- and metaphyseal bone defects predominantly of the lower extremity. CONTRAINDICATIONS: Intraarticular bone defects, persisting bone infection or osteomyelitis, insufficient soft tissue coverage in the region of the bone defect, osteoporosis. SURGICAL TECHNIQUE: First surgical intervention: thorough bone debridement and soft tissue coverage, implantation of a cement spacer into the bone defect for the induction of a synovial foreign-body membrane, internal or external fixation. Second surgical intervention: removal of the cement spacer and filling of the bone defect with autologous cancellous bone graft, optionally internal fixation after initial external fixation. POSTOPERATIVE MANAGEMENT: Partial to full weight-bearing after the first surgical intervention depending on pain. Partial weight-bearing (max. 15 kg) after the second surgical intervention, until radiological signs of a remodeling of the regenerate bone occur. Usually no implant removal. RESULTS: A total of 6 patients (4 men, 2 women) aged 15-66 years with average bone defects of 7 cm (range 4-10 cm) were treated using the Masquelet technique. There were 2 aseptic femoral nonunions and 4 tibial nonunions (2 septic and 2 aseptic nonunions). One case was a periprosthetic tibial bone defect. Bone stabilization after debridement was performed using ring fixators on the tibia and an intramedullary nail and a locking plate on the femur, respectively. The second surgical intervention was performed after 6-9 weeks. In 3 of the 4 tibial cases, internal fixation was performed during this intervention. The iliac crest and the RIA (reamer-irrigator-aspirator) technique were used for cancellous bone grafting. Amputation after breakage of the plate was necessary in the patient with the periprosthetic bone defect. Nonunion at the docking site required cancellous bone grafting in 1 patient. All 5 patients were able to perform full weight-bearing without pain after 6 months. The Ilizarov fixator was removed 5 months after the second surgical intervention in a 15-year-old patient. None of the other implants were removed.

Osteoanabolic effect of alendronate and zoledronate on bone marrow stromal cells (BMSCs) isolated from aged female osteoporotic patients and its implications for their mode of action in the treatment of age-related bone loss.

SUMMARY: In the present study, we evaluated the potential for aminobisphosphonates to enhance the development of bone-forming osteoblasts from progenitor cells isolated from aged female osteoporotic patients. The aminobisphosphonates tested significantly enhanced osteoblast formation and thus lend further insights into their possible mode of action in the treatment of osteoporosis. INTRODUCTION: The primary aim of this study was to evaluate the influence of aminobisphosphonates on the osteogenesis of human bone marrow stromal cells (hBMSCs) and mineralization of differentiating bone-forming cells isolated from osteoporotic patients. METHODS: The influence of aminobisphosphonate treatment on hBMSC osteogenesis was assessed by the quantitative measurement of alkaline phosphatase (ALP) activity, in addition to quantitative reverse transcription polymerase chain reaction and Western blot analysis of known osteogenic markers. Mineralized matrix formation by hBMSC-derived osteoblasts was visualized and quantified using Alizarin red staining. RESULTS: hBMSC cultures treated with osteogenic medium supplemented with zoledronate demonstrated a significant increase in Alizarin red staining after 3 weeks as compared to cells cultured in osteogenic medium alone. Similarly, cultures of differentiating hBMSCs isolated from patients receiving alendronate treatment also demonstrated an increased propensity for mineralization, even in the absence of further in vitro stimulation by zoledronate. The stimulatory effects of aminobisphosphonate treatment on hBMSC-derived osteoblast-mediated mineralization were independent of any alterations in ALP activity, although significant decreases in the expression levels of osteopontin (SPP1) were evident in hBMSCs following exposure to aminobisphosphonates. Further analysis including Western blotting and loss-of-function studies revealed osteopontin as having a negative influence on the mineralization of differentiating osteoporotic bone-forming cells. CONCLUSIONS: The results presented here demonstrate for the first time that aminobisphosphonate treatment of osteoporotic hBMSCs enhances their capacity for osteoblast formation and subsequent mineral deposition, thus supporting the concept of aminobisphosphonates as having an osteoanabolic effect in osteoporosis.

Characterization methods of bone-implant-interfaces of bioresorbable and titanium implants by fracture mechanical means.

Bioresorbable materials for implants have become increasingly researched over the last years. The bone-implant-interfaces of three different implant materials, namely a new bioresorbable magnesium alloy, a new self-reinforced polymer implant and a conventional titanium alloy, were tested using various methods: push-out tests, SEM and EDX analyses as well as surface analyses based on stereoscopic 3D pictures were conducted. The fracture energy is proposed as a very significant reference value for characterizing the mechanical performance of a bone-implant system. By using a video-extensometer system instead of, as is commonly done, tracking the movement of the crosshead in the push-out tests, the accuracy of measurement could be increased.