Over the last decade, 3D bioprinting has received immense attention from research communities to bridge the divergence between artificially engineered tissue constructs and native tissues.

Nature’s materials have evolved over time to be able to respond to environmental stimuli by generating complex structures that can change their functions in response to distance, time, and direction of stimuli. A number of technical efforts are currently being made to improve printing resolution, shape fidelity, and printing speed to mimic the structural design of natural materials with three-dimensional printing. Unfortunately, this technology is limited by the fact that printed objects are static and cannot be reshaped dynamically in response to stimuli. In recent years, several smart materials have been developed that can undergo dynamic morphing in response to a stimulus, thus resolving this issue. Four-dimensional (4D) printing refers to a manufacturing process involving additive manufacturing, smart materials, and specific geometries. It has become an essential technology for biomedical engineering and has the potential to create a wide range of useful biomedical products. This paper will discuss the concept of 4D bioprinting and the recent developments in smart materials, which can be actuated by different stimuli and be exploited to develop biomimetic materials and structures, with significant implications for pharmaceutics and biomedical research, as well as prospects for the future.

This paper aims to investigate the effects of fiber hybridization technique on the mechanical behaviors of non-absorbable braided composite sutures. Fifteen types of hybrid braided sutures (HBSs) made of polyester (PET), polypropylene (PP), and polyamide 6 (PA6) are produced and tested to measure ultimate tensile strength (UTS), maximum strain, elastic modulus, and breaking toughness. Based on the results, it is observed that the suture material plays a significant role in the tensile and mechanical performance of HBSs, and they can be tailored through the different combinations of yarns according to the required mechanical properties. Experiments exhibit occurrence positive hybrid effect in both maximum strain and elastic modulus, and negative hybrid effect in UTS. The optimal tensile performance is associated with the hybrid structure comprising 75% PA6-12.5% PET-12.5% PP. This means the ternary structure with higher PA6 content along with PP and PET, demonstrates a synergistic effect. Thus, such a ternary composite structure is very promising for the design of novel non-absorbable sutures. Due to the absence of similar results in the specialized literature, this paper is likely to advance the state-of-the-art composite non-absorbable sutures and contribute to a better understanding of the hybridization concept for optimizing composite material systems.

This paper presents an experimental investigation of the hybridization impacts on the tensile performance of the two-dimensional (2D) braided tubular composites by varying the types of constituent fibers and combination. Fifteen types of tubular braids with different combinations of three types of yarns - polyester (PET), polypropylene (PP) and polyamide 6 (PA) - were produced on a braiding machine. Subsequently, the vacuum infusion process (VIP) was adopted for the fabrication of hybrid braided composites (HBCs). The hybridization of the yarns with different mechanical properties was carried out so that the influence of the fiber type and ratio on the tensile behavior of the HBCs could be recognized. The mechanical properties (i.e. ultimate tensile strength (UTS), strain at failure, modulus of elasticity and fracture toughness) of HBCs were evaluated, and different types of HBCs were compared against one another to understand the benefits of hybridization and the resulting performance enhancements. Afterward, HBCs with the most satisfying mechanical performance were determined based on the scoring each of the evaluated mechanical parameters. The results indicate that the ternary hybrid composite with a combination of 75% PA-12.5% PET-12.5% PP presents the highest values of tensile performance. Besides, this study reveals that the reinforcement materials and their ratio play a significant role in tensile performance, and also the interaction within each pair of constituent fibers could alter the nature of the final behaviors. Finally, our findings exhibit the existence of positive and negative hybrid effects in UTS, strain at failure, modulus of elasticity and fracture toughness.

The development of flexible optical waveguides for biophotonics requires materials that combine mechanical compliance, optical transparency, and tunable refractive index (RI). This study reports the fabrication of polydimethylsiloxane (PDMS)‐based nanocomposite thin films (NCTFs) incorporating 1 wt% ZnO and TiO ₂ nanoparticles(NPs). NP dispersions are optimized using response surface methodology with a Box–Behnken Design, enabling reproducible control of sonication parameters. This optimization produces sub‐70 nm particle sizes, minimizing Rayleigh scattering at 635 ± 5 nm and directly linking dispersion quality to optical performance. The NCTFs exhibit RI enhancements (1.4149 ± 0.0006 for ZnO and 1.4146 ± 0.0005 for TiO ₂ ), high transparency (>96% for 2 µm films; 97.6% and 82.0% for 60 µm ZnO and TiO ₂ films, respectively), and guided‐mode optical losses of 0.86 and 2.55 dB cm ⁻¹ . Mechanical characterization confirms Young's moduli below 0.53 MPa and surface roughness below 7.02 nm, while FTIR analysis verifies the chemical integrity of the PDMS network. Comparative evaluation reveals composition‐dependent trade‐offs: ZnO composites offer a balanced profile of transparency and compliance, whereas TiO ₂ composites provide stronger RI modulation but higher optical loss. This integrated materials–processing–performance framework establishes a reproducible route toward multilayer waveguides and soft photonic systems for wearable and implantable biomedical devices.