Polyhydroxyalkanoates: the natural biopolyester for future medical innovations.

Polyhydroxyalkanoates (PHAs) are a family of natural microbial biopolyesters with the same basic chemical structure and diverse side chain groups. Based on their excellent biodegradability, biocompatibility, thermoplastic properties and diversity, PHAs are highly promising medical biomaterials and elements of medical devices for applications in tissue engineering and drug delivery. However, due to the high cost of biotechnological production, most PHAs have yet to be applied in the clinic and have only been studied at laboratory scale. This review focuses on the biosynthesis, diversity, physical properties, biodegradability and biosafety of PHAs. We also discuss optimization strategies for improved microbial production of commercial PHAs via novel synthetic biology tools. Moreover, we also systematically summarize various medical devices based on PHAs and related design approaches for medical applications, including tissue repair and drug delivery. The main degradation product of PHAs, 3-hydroxybutyrate (3HB), is recognized as a new functional molecule for cancer therapy and immune regulation. Although PHAs still account for only a small percentage of medical polymers, up-and-coming novel medical PHA devices will enter the clinical translation stage in the next few years.

Biomimetic natural biomaterials for tissue engineering and regenerative medicine: new biosynthesis methods, recent advances, and emerging applications.

Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering (TE) and regenerative medicine. In contrast to conventional biomaterials or synthetic materials, biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix (ECM). Additionally, such materials have mechanical adaptability, microstructure interconnectivity, and inherent bioactivity, making them ideal for the design of living implants for specific applications in TE and regenerative medicine. This paper provides an overview for recent progress of biomimetic natural biomaterials (BNBMs), including advances in their preparation, functionality, potential applications and future challenges. We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM. Moreover, we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications. Finally, we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.

A foreign body in the blood vessel: A diagnostic and therapeutic dilemma.

Foreign body(FB) in soft tissue is a common injury in trauma, but it is rare for FB to enter the blood vessel. Typical causes of intravascular FB include iatrogenic and non-iatrogenic factors.A 65-year-old Chinese worker's left hand was hit by two colliding metal blocks while operating a machine tool. Then, he referred to our hospital's emergency department of orthopedics. The X-rays showed that metal FB could be seen in trapezium bone regions of the left hand. During the operation, the FB was found in the cephalic vein of his left hand, so the FB was removed by surgery. After six weeks of follow-up, he has returned to normal working conditions.The purpose of this article is to describe the diagnosis and treatment of a rare condition in the emergency department. In our emergency work, it is easy to miss the diagnosis of intravascular FB caused by trauma. To our knowledge, this is the third reported intravascular FB caused by trauma and the first reported intravascular FB was located in the vein of the hand. Detailed medical history and auxiliary examinations are the key to the diagnosis of FB in the blood vessels.

Risk factors for implant failure after fixation of proximal femoral fractures with fracture of the lateral femoral wall.

INTRODUCTION: To investigate potential predictors of implant failure following fixation of proximal femoral fractures with a fracture of the lateral femoral wall. MATERIALS AND METHODS: Medical records of 99 adult patients who had operative treatment for a proximal femoral fracture with a fracture of the lateral femoral wall between May 2004 and April 2015 were retrospectively analysed to determine factors associated with implant failure. Patients underwent routine surgical procedures for implantation of extramedullary or intramedullary devices. Potential predictors were age, gender, body mass index, comorbidities, type of fracture, reduction method, status of greater and lesser trochanters, course of the lateral fracture line, and presence/absence of a free bone fragment at the junction of the greater trochanter and lateral femoral wall. RESULTS: Ten (10%) implant failures were identified. Univariate analysis identified a free bone fragment at the junction of the greater trochanter and lateral femoral wall (odds ratio [OR], 21.25; 95% confidence interval [CI], 4.31-104.67; p < 0.001) and a transverse fracture line across the lateral femoral wall (primary or iatrogenic) (OR, 5.36; 95% CI, 1.29-22.30; p = 0.021) as factors associated with implant failure. Using a multivariate model, only a free bone fragment at the junction of the greater trochanter and lateral femoral wall (OR, 16.05; 95% CI, 3.06-84.23; p = 0.001) was a risk factor for implant failure. CONCLUSIONS: A free bone fragment at the junction of the greater trochanter and lateral femoral wall and a transverse fracture line across the lateral femoral wall are predictors of implant failure in proximal femoral fractures with a fracture of the lateral femoral wall. Integrity of the lateral femoral wall correlates with prognosis of proximal femoral fracture. Lateral femoral wall reconstruction may be required for effective treatment of proximal femoral fractures with a fracture of the lateral femoral wall.